Small rooms made to test stuff, they're often mishmashes of normal stuff filled with test NPCs and/or items. Because the developers probably tested stuff with console commands on, a lot of these cells are completely dark by default. Similar to the test NPCs, their internal name will be given in order to prevent confusion as these cells will oftentimes share a name or not have one at all. Also of note, these are all test cells that are not connected to The Testing Hall, as those are listed separately.
AnvilMarkTest
Form ID: 0003E2B8
Name: [Blank]
A small square room (3 by 3 "sections") with stone walls and wooden columns. No door, despite an area on one wall where a door would be placed. The Mark mentioned here is probably quest designer Mark Nelson. We can also assume that Anvil refers to the city, not the object.
ChorrolMarkTest
Form ID: 000245A4
Name: MarkTest
The same room as the Anvil test, but now with people and stuff inside. The Wabbajack, Sanguine Rose, and Skull of Corruption are present on the ground. One of the NPCs present, Test High Elf, knows a spell called "MarkSkullTest", which might tie him to the Skull of Corruption at the very least. The reason for inclusion of the other staffs is unclear. There are also five numbered markers placed in this cell prefixed with "MarkSpellTestMarker". The NPC this NPC isn't actually set up to use these markers, and he doesn't seem to use the spell in combat either, since that isn't really feasible in this small room.
The other NPC present is linked to the other object in the room, a gravestone. It reads "Here Lies Vena Petilius", which you may recognize, as there's another grave used in the final game with the exact same text. That grave is visited during the Molag Bal quest, and the central NPC in that quest uses a special marker to pray at the grave. That's what this NPC's purpose was as well, although he doesn't have a unique animation set up. Also, his AI package makes him use the marker constantly, which looks quite buggy.
GuardConvoTest
Form ID: 0006FDB7
Name: [Blank]
A farmhouse interior inhabited by three guards, two of which are test NPCs. The cell seems to have been made just to test the guard convo system.
TestAlan
Form ID: 00012A85
Name: [Blank]
There are basically three points of interest here. First are the tables that are filled with almost all unique miscellaneous quest rewards you can get in the base game. Then there's also the model of Garridan fighting a Frost Atronach, this time not encapsulated in ice so you can take a closer look. And then thirdly is a test NPC called "Kill me". There's also a marker placed in the cell called "MS00TestItems", which might hint at the actual purpose of this cell overall, testing if the quest rewards functioned like intended. Considering this cell is named after quest designer Alan Nanes, it's a likely possibility.
TestAR
Form ID: 00090757
Name: [Blank]
AR seemingly stands for "Ayleid Ruin" in this case. We find ourselves in a badly lit, badly made Ayleid Ruin, alongside two test skeletons. Very barren, basic, and nothing really to write home about. Its function is also not clear.
Testarena
Form ID: 000250A4
Name: [Blank]
A basic version of the Chorrol/Imperial City arena that's pretty badly lit. In the vanilla game, there are no NPCs or enemies present here.
With the Knights of the Nine DLC, one instance of Umaril and the NPC "TestBruce" can be found here, while the Shivering Isles DLC adds another instance of "TestBruce" and a Diseased Scalon. This was probably done either to test these monsters' combat effectiveness, or just for the amusement of the developers.
TestarenaJonPaul
Form ID: 00061BD9
Name: [Blank]
Exactly the same layout as the cell above, although this time with a Golden Saint and a basic patrol route setup. Again, this cell was just empty before the Shivering Isles DLC made use of it. The name of this cell also references developer Jon Paul Duvall who's credited under Additional Design.
TestarenaKurt
Form ID: 000CB8BE
Name: [Blank]
Once again the same basic cell, although this time without any inhabitants, instead featuring a marker called "TestKurtMarker". Unknown what its purpose was, and Quest Designer Kurt Kuhlmann doesn't drop any other hints either. With the Knights of the Nine DLC, one light source gets added, but this doesn't make the purpose any clearer.
TestBrumaHouseInt
Form ID: 0001540D
Name: Bruma House Test
This cell can be accessed by entering the biggest house in the circle of Bruma houses that are present in the test world "TestGragTown". This is actually an early version of Baenlin's house, with the majority of the functions being the same in the final game. Even the minotaur head for the Dark Brotherhood quest is already present here, although it can't be activated. There are also no NPCs present.
Also, for some reason, someone at Bethesda thought it would be a good idea to reuse this cell for the Frostcrag Spire DLC. As such, with said DLC, the interior gets changed and the cell name gets altered to "FrostcragSpire01".
TestBrumaHouseMid
Form ID: 00018093
Name: TesterHouseBrumaMid
Another cell that can be accessed from a different Bruma house in the aforementioned circle. The door is owned by actual Bruma resident J'Ghasta but besides that, this is just a test for Bruma house decoration, not even J'Ghasta's house, just a basic Bruma middle-class house.
Just like the cell mentioned above, this one also gets altered by the DLC, and turns into "FrostcragSpire02".
TestBrumaHouseMid02
|
This needs some investigation. |
Form ID: 0001B836
Name: TesterHouseBrumaMid
Despite its place of access being the same as before, and the unsuspecting name, this cell isn't a test for Bruma houses. Rather, this cell contains some interior parts of the Oblivion sigil towers. This comes complete with sigil stone that can be activated, and for whatever reason, will fill up your inventory with sigil stones.
This cell receives the same fate as the two previous ones, becoming "FrostcragSpire03".
TestCameronCave
Form ID: 00038B49
Name: Caverns
A basic cave layout inhabited by a single Daedroth, nothing noteworthy. The name is quite baffling, as there isn't a single Cameron mentioned in Oblivion's credits. It’s also unlikely that it's a misspelling of or on wordplay "Camoran", since there isn't anything tying him to the cave.
TestCastleInterior
Form ID: 0002806C
Name: Test of Castle Interior Pieces
The name of this cell is quite incorrect, as this cell is just an empty void, only containing a single ladder and a trapdoor that are linked to each other.
TestCave01
Form ID: 00034E1D
Name: Caverns
A bland, unremarkable cave interior without any props or enemies. Might've just served to test the functionality of the cave assets. There's also a door present that leads to the following cell.
TestCave02
Form ID: 000034FF
Name: Caverns
Another unremarkable cave interior, but this time with some cairn bolete mushrooms present! This cell has the aforementioned door leading back to the previous cell, as well as a door leading to the next cell.
TestCave03
Form ID: 00034E1E
Name: Caverns
The smallest of unremarkable caverns, this one only has a door leading back and nothing else of note.
TestCave04
Form ID: 000183F0
Name: [Blank]
This one can't even be called a cave, it's just a passage with a splitting path and two light sources.
TestCave05
Form ID: 0001DF79
Name: Small Room Test
A small cavern room, decorated with four crypt tombs, and finally an enemy present in the form of a test goblin called "XXXCreatureGoblin" internally. This is the only instance of this test creature placed anywhere.
TestChairs
Form ID: 0002ECC6
Name: Chair testing
A cell for… Testing chairs. It's just a small farm room layout, filled with numerous tables and chairs. Yay?
TestChappy
Form ID: 00027811
Name: [Blank]
A test cell made by developer Brian "Chappy" Chapin, it consists of only three things. A basic barracks model, a single light source, and a test NPC for the player to kill.
TestCheydinhal
Form ID: 0001E735
Name: [Blank]
Literally just a void with a middle class Cheydinhal house model and fitting door.
TestCheydinhalUpper
Form ID: 0001EEEC
Name: [Blank]
Another void, but with more Cheydinhal house models, consisting of two middle class interiors, three upper class interiors, one upper class exterior, and the interior and exterior for the local Mages Guild.
TestCitadel
Form ID: 00035A3B
Name: [Blank]
A void with some architecture pieces that one would normally encounter in an Oblivion citadel.
TestCitadelLighting
Form ID: 00047AEE
Name: Daedric Citadel
Similar to the previous cell, although now featuring only light beams.
TestClara
Form ID: 000253FC
Name: [Blank]
Two barren shipwrecks floating in a void, travel is possible via Chorrol-style trapdoors. "Clara" likely refers to Clara Cafasso of the World Art team, which may imply these were just made to check certain assets that were made.
TestClara02
Form ID: 0001802D
Name: [Blank]
A castle-style room, featuring thrones, rugs and platforms from the Anvil, Bravil, Bruma and Leyawiin castles. Also present is Lorgren Benirus' hand for whatever reason.
TestClaraTangent
Form ID: 000CB50A
Name: [Blank]
A void cell with multiple unconnected pieces of architecture. It features, for example, a piece of Anvil's castle, the Anvil Lighthouse, as well as a normal house and the Mages Guild Building. Then there are parts of the Hist tree room normally found in the Blackwood Company's Basement in Leyawiin, as well as a ship lamp, a shipwreck, and the body of Lorgren Benirus. At least he made a reappearance?
TestDan02
Form ID: 00088835
Name: Gauntlet Test
Two basic, barren rooms in Ayleid architecture that are connected. It's unclear as to what gauntlet the name refers to, or what this was meant to test exactly. The cell is named after a certain "Dan", which refers to either Dan Teitel of the Programming team, or to Daniel T. Lee who's credited under the Additional World Art team.
TestDan03
Form ID: 000B6C11
Name: Imperial City Collision Testing Area
A void filled with numerous Imperial City interiors. Based on the name of the cell, it was made to check the collision of these areas.
Testdungeon
Form ID: 0001806A
Name: [Blank]
Very accurate internal name, just a very basic cave layout with nothing inside.
TestFaces
Form ID: 0003FA94
Name: Test Faces Here
One of many test cells that can be tied to developer Todd Howard. His cells almost always feature the same basic room layout, as well as some of the same items and NPCs. This is presumably due to him or someone else just copying them and altering them slightly. Like the name states, this cell was used to test the visual differences in NPCs' faces when altered by the age slider. There are six male and six female NPCs present for this purpose on the top and bottom floors of the house. Also present on this floor is a table with gold, a steel mace, a steel war axe, an urn, a goblet, and three of Todd's test books. The last things present on this floor are two test containers, and one instance of the test NPC Alban Corinis. While the females are up above, the males are down below, as well as a bed, a chair, and an evidence chest. The door and the light sources in this cell are also test duplicates, for whatever reason.
TestFarmHouse03
Form ID: 0002729D
Name: Grant's Farmhouse Interior Test
While this cell has the number three attached, all other related cells have been deleted. It's possible that this cell was made just to test the farmhouse interior layout, since there isn't much going on. In the cellar area there are six bottles of wine and a silver pitcher, and that's all the decoration in the farmhouse. In the attic, however, we will encounter a zombie called "ZombieMixnMatch03". Internally it is known as "TestZombieGrant" which signifies that it was just a duplicate made by Grant for this test cell. This is notable because there are already six numbered "mix and match" zombies set up called TestZombie, and Grant seems to have made a duplicate of number three. (They are called mix and match because they variably lack arms and a head, and were probably used to test if this looked okay.)
For whatever reason there's another "room" present in this cell which is normally inaccessible because it’s located out of the boundaries of the farmhouse. We’ve got some sigil tower Oblivion architecture here looking pretty terrible. Also present are the Dark Brotherhood minotaur head and its fastenings because, why not, and some vats alongside some floating doors. The Grant mentioned here likely refers to Grant Struthers of the World Art team.
TestFavelas
Form ID: 000CBA64
Name: [Blank]
The word favela refers to a slum, so as expected this cell holds some lower-class housing. There are three Bravil interiors, one Leyawiin interior, a Bravil door, a Bravil rope, and weirdly enough some Kvatch architecture pieces.
TestFireLights
Form ID: 0002D2FD
Name: [Blank]
The Weynon House interior with multiple different fire types spread throughout. Based on the name, this cell was made to test the light caste by these fires.
TestFireSounds
Form ID: 000C5418
Name: [Blank] A big mine room containing numerous flames, based on the name of the cell, it was made to test the sounds emitted by said flames.
TestFog
Form ID: 0007BAA4
Name: [Blank]
A very basic cave room with some fog made in order to… Well, guess.
TestFrank
Form ID: 00033D34
Name: Nisin Cave
While this is essentially just another bland, empty cave cell, the name is quite interesting. Nisin Cave is the name of a cave that appears in the final game, so this may have been a very early version of it. That, or a duplicate for test purposes, although that seems unlikely. The Frank mentioned here is probably Frank Ward of the Dungeon Art team, due to… Well, this being a dungeon and all.
TestGrantWarehouseUpper
Form ID: 00029077
Name: Grants messed up upper warehouse
A copy of the warehouse cell "WarehouseUpperClass", although for some reason all the ground has been deleted. Besides this, the cell is identical. Its purpose is unknown.
TestGuy
Form ID: 0001C611
Name: TestGuy
The first of many copies of Todd Howard's test cell, in comparison to the last version, there are no NPCs now, no gold and no bed, chest or chair. All other items such as the books, weapons and table are still present, however. There's now also a skeleton, normally used during the opening exclusively, draped over the staircase railing. That, and the door is now oriented incorrectly. This cell's purpose is unknown, but the name probably refers to Lead Programmer Guy Carver.
TestHavok
Form ID: 00049525
Name: [Blank]
The cell’s name refers to the Havok physics engine, which is the system Oblivion uses for its physics. Seeing as something as primitive as having real-time physics was a first for the series, and it's still quite wacky in Oblivion; it's not surprising that they have a cell dedicated to testing it out. The cell is nothing to write home about, just some cave interior with bones scattered around.
TestHavokSettle
Form ID: 0006A5C9
Name: [Blank]
Basically the same thing as before, but this is more to check how objects behave when you load into a cell, and they might jiggle around a bit. This can mostly be soon with the books on the bookshelves. This appears to be a duplicate of the upstairs portion of the Chorrol Mages Guild.
TestHL
Form ID: 00000888
Name: [Blank]
This cell is basically empty, only containing a standard XMarker, and a static object called "testGass", which no longer has a corresponding mesh/model. It's completely unknown what this cell's purpose was.
TestICTowers
Form ID: 0004986C
Name: Megan's test cell
A test cell to check how the Imperial City tower pieces worked in action. For some reason, there are also a lot of containers hidden underground. There are actually multiple interiors which can only be accessed by noclipping, as they aren't directly connected to each other, but they all serve the same purpose. The name of this cell, "Megan's test cell", also links it to Megan Sawyer of the World Art team.
testIst
Form ID: 000009EA
Name: [Blank]
A weird Ayleid dungeon with some torture cages present as well. The only notable thing here is a marker that's normally used for the Thieves Guild quest "The Ultimate Heist". Which may imply this cell was a testing room for the dungeons seen during that quest, though it's not really clear. It's also unknown what the "Ist" in the name "testIst" refers to.
TestIst2
Form ID: 0002D8D2
Name: [Blank]
A copy of the Imperial Subterrane, one of the cells you normally go through during the tutorial. Nothing interesting to be seen here, although this opens up the option that TestIst may stand for Test Imperial Subterrane.
testist3
Form ID: 000056A1
Name: [Blank]
This cell is another Ayleid ruin, so maybe the Imperial Subterrane isn’t connected after all. There are some traps present here, but this cell holds one interesting thing, a test variation of a zombie. It’s internally known as “TestIstZombie01” but there are no other numbered instances. Again, it’s unknown why a testing variant was needed here, since they could’ve just used a regular zombie, or another testing variant instead of making a unique one.
TestIst4
Form ID: 00094190
Name: [Blank]
A generic cavern dungeon, but for some reason it's filled with a random assortment of enemies, including a frost atronach, a storm atronach, a minotaur, a Daedroth, a Land Dreugh, an Ogre and a spider Daedra.
TestJuanGoblinLair
Form ID: 000359DC
Name: Interior Cave Test
Of course, this cave does not contain any goblins. It's called "Interior Cave Test", so we can assume that it really was more important to check if the cave's interior worked, rather than enemies. That also means that it's likely a very early test cell. Juan here refers to Juan Sanchez of the Character and Creature Art team.
TestKenHole
Form ID: 000297A6
Name: TestKenHole
This cell is just completely empty. The name refers to Lead Designer Ken Rolston.
TestKK
Form ID: 00023187
Name: [Blank]
A basic house interior with two candles present, one pair of chainmail boots, and two testing NPCs. The male NPC is called "TestClothes" and he does not wear any clothes. He does, however, wear the Colovian signet ring of Count Ormellius Goldwine, which is… one of the most random choices possible, but sure, why not. The female NPC is called "TestKKWoman" and she wears lower class outfit six, consisting of buckled shoes, green felt lines, and a collared shirt. She has nothing else notable about her. And that's the entire cell, don't know what the point was, but it had something to do with clothes, I'm almost sure of it. The KK probably refers to Kurt Kuhlmann.
TestKurtDetection
Form ID: 000055BC
Name: Collapsed Mine - Breakthrough
The purpose of this cell is basically explained by its internal name. Its other name, though, is quite interesting. "Collapsed Mine - Breakthrough" is a cell seen in the final game, which basically means we’re dealing with a copy of an existing cell to test something specific again. The cell is inhabited by a single NPC called "TestDetection" that's just a stock Khajiit bandit otherwise. There are also eight markers referencing detection testing, but there's nothing else notable about this cell.
TestMattInterior
Form ID: 000231B6
Name: [Blank]
Like the name implies, we can find numerous interiors here that were probably checked for issues before being put into the game. Present here are cathedral interiors, as well as interiors for both Chorrol and Cheydinal houses. Some interiors also feature a bit of clutter, but nothing noteworthy.
TestMegan
Form ID: 0003051A
Name: Megan's test cell
In the vanilla game, this cell just consists of some Imperial city basement architecture, as well as three linked copies of the Mages Guild Portal.
With the Knights of the Nine DLC, all the ground gets deleted for some reason, but two Mages Guild portals remain. There is also a static object placed called "NDPriory01" that no longer has a corresponding model, as well as an object that can be activated called "NDPrioryAnimatingStairs01" internally, which would’ve given the prompt "Knights of the Nine Symbol".
TestMegan02
Form ID: 00025E38
Name: Megan's test cell
This cell consists of numerous Imperial city interiors with some basic decorations, and Cheydinhal-style lights.
TestMegan03
Form ID: 0003E243
Name: Megan's test cell
An Imperial City interior full of clutter, unlit under normal circumstances, and completely unremarkable.
TestMegan04
Form ID: 0006FDE2
Name: Imperial City Collision Testing Area
This cell contains all Imperial city interiors, it should be clear as to why.
TestMine
Form ID: 000338A3
Name: [Blank]
Another one of those cells that has their whole point explained by their name. This is just a cell, apparently made to test mine dungeon architecture. It doesn't contain anything noteworthy.
TestMist
Form ID: 00033F59
Name: [Blank]
A basic cave dungeon interior meant to test mist. There are also three instances of a test leveled list used here called "ZombieTestLeveled" ; the list itself contains normal and headless zombies, no test variations.
TestMRyan
Form ID: 000327CB
Name: Mike's Test Cell of Madness
Don’t let the name fool you into thinking this is a Shivering Isles test cell, as it isn't. Michael E. Ryan of the Dungeon Art team just seems to be a wacky guy. The cell itself isn't that strange. It consists of fort ruin architecture, with not all parts being easily connected. The most "madness-y" thing here is the fact that these madmen of Bethesda leave their dungeons unlit. There's also a room which contains Paradise mudcrab variants, which is pretty quirky. There are three other points of interest. First off is a door which is a test copy called TestMikeDoor. Again, pointless duplicate, but sure. There are also two test chests internally known as "TestMikeBrute" and "TestMikeThief". These names refer to the classic class trope of RPGs. The brute chest contains items a brute would use, and the same for the thief. Since the mudcrabs are the only enemies found here, they're kinda pointless.
TestOblivionLift
Form ID: 00085FC1
Name: Test for Oblivion Lifts
Besides its name, it doesn’t have anything else leftover and is just empty. Also, the "lifts" referenced here are actually the runed portals usually found in Oblivion Sigil Keeps, notably the Kvatch one, which is also the only one where the portals are referred to as "Lifts".
TestParadiseCave
Form ID: 0005D36A
Name: Paradise Cave
As the name implies, this is an early version of the Lair of Anaxes - the cave in which Anaxes is trapped in Paradise. The most notable thing here is the fact that Anaxes is not present at all, in his place there’s a test Xivilai. Its internal name is just "TestCreatureXivilai01" but its actual name differs just a bit "TestCreatureXivilaiHugh01". That ties this creature to Hugh Riley of the Character and Creature Art team.
This also another test cell that got repurposed for a DLC, this time the Thieves Den DLC. Its interior gets completely changed, as well its internal name to "DLDunbarrowHaven" and its visible name to "Dunbarrow Cove".
TestParticles
Form ID: 00035A2C
Name: [Blank]
This is just a void with the secret prison wall normally seen during the opening. I'm not kidding.
TestPhantomTraps
Form ID: 00047B5F
Name: [Blank]
This is just another Ayleid ruin featuring swinging blade traps, or well, a testing variant of the swinging blade trap. In this case the test duplicate makes sense, as this one uses a different script to make it work. In the final game there are four different variations of how these traps can work. This is likely an earlier attempt, before the developers realized they needed a different method, and thus the final game's swinging blade traps were born.
TestQuest01
Form ID: 000314EA
Name: [Blank]
This might once have held something related to a testing quest. Now, it's completely empty though.
TestRyan
Form ID: 000A29B3
Name: [Blank]
The name likely refers to Ryan Sears of the Additional World Art team. This cell consists of both an Imperial city interior layout and a basic cavern layout, although there's nothing going on in either of them.
TestRyanOgre
Form ID: 000AA26A
Name: [Blank]
This cell is a small tunnel system that loops around, it contains a single Daedroth. Yup, a Daedroth, no Ogre to be found anywhere.
TestSeveredHead
Form ID: 0001ED41
Name: [Blank]
A basic Chorrol interior with a fire lit in the fireplace, but no severed head to speak of. It's possible that this cell was once used to test the "Mother's Head" static item seen during the Dark Brotherhood questline.
TestSewersXX
Form ID: 0004B7B5
Name: Sewers
Don't worry about those X's, the only thing giving kisses in this cell might be the four rats present. This just seems to be a basic room layout test. It also doesn't seem like this sewer part is ever directly reused in the final game, or maybe it is, but all sewers parts are basically indistinguishable from one another.
TestShrine
Form ID: 0003347A
Name: Dagon Shrine
A test version of the Mehrunes Dagon Shrine as seen in the quest, uh, Dagon… Shrine. It’s just a basic cave layout with an altar containing the Mysterium Xarxes of course. There are two Mythic Dawn members present in the room as well as a dagger next to the book on the altar, and a silver claymore in a barrel nearby. Something notable is that the statue to Mehrunes Dagon isn't even a statue to him here, it's just a generic Ayleid Ruin statue.
Once again, this cell was repurposed for the Thieves Den DLC. It was turned into the cell "Captain's Quarters", internally known as "DLDunbarrowHaven02".
TestSkingradCastleInterior
Form ID: 0002B2AD
Name: [Blank]
The existence of this cell implies that either A) the interior of castle Skingrad was once just one big zone without loading doors, or B) Bethesda actually maps out their zone as one big thing before splitting it up. Despite the latter actually being a good way to check if everything makes sense space-wise, one might lean towards the former explanation, which is a cool concept but probably a bit too stressful on the engine back in the day.
TestStairs
Form ID: 0002A66C
Name: [Blank]
This cell is basically TestSewers, part two. Just a basic sewer room layout, this time featuring stairs, wow.
TestStealth
Form ID: 0002D31D
Name: Stealth Test
In the same vein, this cell is basically just a generic Castle room again. It also contains two test NPCs, one disguised as a Chorrol guard, and the other as a thief. The Thief is called "Stealth Test Guy -- Not Alert" and the guard is called "Stealth Test Guy -- Alert". Despite their names and supposed roles, you won't actually notice any differences in how they will notice the player, and there don't seem to be any as that's normally controlled by scripts, which neither NPC possesses. They do share a faction called Stealth Test Guards, which makes them like each other. So ultimately it seems that the player needed to be the stealthy one in this scenario, and once again it doesn't actually seem to test what it set out to.
TESTTavernTempCOPY0000
Form ID: 0003134D
Name: [Blank]
If the overflow of buzzwords didn't give it away, this appears to be a duplicate of a temporary version of a tavern cell. And it's just that, just a standard farmhouse interior. It's referred to as a tavern, but there's nothing really indicating that otherwise.
TESTtempinterior
Form ID: 000281E2
Name: temp interior mockup
A very basic house interior mockup, and you can guess in the style of which city it's done, it'll probably shock you.
TestTemple
Form ID: 00181D21
Name: [Blank]
Literally just a barren, empty copy of the Temple of the One.
TestTimFireColumn
Form ID: 000C50EA
Name: The Blood Feast
Literally just a fire column, great. The name of the cell is "The Blood Feast", which is the same as the Sigil Keep in the Kvatch Oblivion zone, so this was likely made to test its effect. Likely also quite early on in development. The Tim mentioned in the internal name is probably Tim Lindsey from the Dungeon Art team.
TestTimOblivionLords
Form ID: 000C46F0
Name: Sigillum Sanguis
A copy of a generic Sigillum Sanguis, which is the incorrect Latin name of the uppermost room in a Sigil Keep in your usual Oblivion World. The name of this cell refers to a marker present here which mentions a "Deadra Lord". First off, actual Daedra Lords don't appear in Oblivion as generic enemies, and secondly, Tim probably meant "Dremora Lord".
This is also the third and final cell that was recycled for the Thieves Den DLC. It got turned into "The Black Flag", internally known as "DLDunbarrowHaven03".
TestToddCrazy
Form ID: 0001C610
Name: [Blank]
Is it just me or does this cell feel… familiar? Well, yeah, since this is just the basic layout of Todd's previous cells again. Although this time he was like "What if I just spam random crap inside of it?" The result is this. The naked face NPCs and general layout remain the same, but the last time we were here, there were no flying steel war axes. Another new addition is the over one hundred flying instances of the "Test Book on Monkeys" internally known as "TestToddFolio01". Sadly, its contents don't have anything about monkeys, rather they're just a copy of "Mythic Dawn Commentaries 2".
Downstairs there's also a unique NPC that hasn't been present before, Todd's Tester Man. The weirdest thing in this cell by far have to be the five t-posing objects in the upstairs corner. We have a headless rat, a headless scamp, a female torso in iron armor, a male torso in iron armor, and a female torso wearing a green brocade doublet (except that one's model has been deleted).
What’s the purpose of this? Well, these objects are just that, static objects. However, they use the mesh and textures of the finished, rigged models. This means there's a big chance that these static models were made just for the convenience of the modeler, this way they could check their model in one piece rather than going through all the individual parts. Both Skyrim and Oblivion have other examples of this. Now, if that's the case, why are these models placed in this cell? Now, that's a question probably only "crazy man" Todd Howard can answer.
TestTraps
Form ID: 0003F153
Name: [Blank]
This is just one of those straightforward cells. Like you could've guessed, the cell is filled with traps to test their functionality. The two most interesting things here are a barrel, which is a test container filled with archery equipment, and some goblins that are meant to test the trap, since they're also testing duplicates. Good cell.
TestVendorInterior
Form ID: 0001E31B
Name: [Blank]
A basic Chorrol interior, decorated with a table on which lie a Blades cuirass and a steel longsword. There's also a book vendor chest present, as well as a test NPC that can't actually be traded with.
TestXenon
Form ID: 0002910F
Name: [Blank]
This is the cell in which the player starts, as in literally, the jail cell. Nothing else besides that cell is present here, if you can call that noteworthy. What is present here are two static objects known as "cellChain01Xenon" and "PrisonSecretWallXenon". Now the word "Xenon" in this context actually refers to the code name of the Xbox 360 while it was still under development. This might mean that some stuff was originally meant to be different on the console, but as it stands now, both the static objects that refer to xenon actually use the same models as they do in any other version. Don't get it, but hey, it’s there. Fun.
ToddDung
Form ID: 000191D5
Name: [Blank]
Yeah, no, the "dung" here actually stands for "dungeon". Whatever this cell once was, the majority of it has been deleted. All that's left are some bones, flames and creatures in a void. The only things noteworthy here are the creatures. The rat is normal, but both the minotaur and the Daedroth are test duplicates. The Daedroth even specifically mentions Todd in its internal name, so Todd probably specifically made it for this cell.
Toddtest
Form ID: 00000812
Name: Todd's Test House
Yet another variation of the "TestFaces", "TestGuy", and "TestToddCrazy" cells. Again, the inside of the cell is completely identical. A Chorrol house, on the bottom floor there's a bed, a chair and an evidence chest. On the upper floor we can find three more test NPC that were previously encountered, two of Todd's test containers that were previously encountered, as well as the two test containers. The most notable difference is that there is now a warhammer and a torch present on the crate, and the four Mythic Dawn Commentary volumes are present on the table.
XXXDELETEME
Form ID: 00015E20
Name: Brina Cross
Another case of a developer apparently ignoring the obvious hint to delete something. This cell is completely empty, but it does bear an interesting name. "Brina Cross" is the name of a crossing of two roads, one of which originally led to the removed city of Sutch. With Sutch's removal, the road no longer was a crossing, and in the final game the "Brina Cross Inn" is placed here.
XXXMiscarcand05
Form ID: 0002C550
Name: Miscarcand Welkynd Stone Room
While you could say that this is just another basic test for a main quest dungeon, this is interesting because the Miscarcand in the final game only has 3 cells. So it might have been way bigger originally. And no, there are no leftovers of the fourth cell that's missing.
XXXRANDOMCave01
Form ID: 0003E2D4
Name: Bleak Flats Cave
Another very early test for a dungeon that appears in the final game. Nice novelty, but nothing really noteworthy.
zClothesTest
Form ID: 000231A1
Name: [Blank]
Another Chorrol house inhabited by two test NPCs. They were used to test something related to clothing, but the NPCs are barely dressed, so whatever it exactly was, is unknown.