Pokémon Yellow

This page details development materials of Pokémon Yellow.

'This page or section details content from theApril 2020 Nintendo Leak.'''

'This page or section details content from theOctober 2024 Game Freak Leak.'''

Pokémon Pink#

The leaked source code for Yellow includes a few mentions of a seemingly never made companion version that would've been called Pokémon Pink. This includes "Pocket Monsters Pink & Yellow", as well as pokemon_type in PM_DEBUG.DEF having the options "yellow package" and "pink package" (although the "pink package" only has a minor effect on the game tied the original Red/Green such as the gender of a Nidoran NPC.).

While it is not certain which Pokémon would have been the mascot of Pink, Clefairy appears to be the most likely candidate, given its coloration and the fact it was originally intended to be the franchise's mascot. An image of a frame that was included in the Japanese release of the Game Boy Camera appears to corroborate this.

Early Sprites#

GS Source Files#

These sprites were found at the very end of a list containing several sprites for an early version of Pokémon Gold and Silver, which itself was found within leaked material for that game. This isn't surprising, as Yellow was being developed around the same time as Gold and Silver. These sprites are labeled with the filename format "PMYF_" ("Pocket Monsters Yellow Front") followed by the corresponding Pokémon's Pokédex number. Worth noting is that Squirtle and Kakuna are also found within this listing, but weren't included in this table due to them already being finalized.

Pokémon Name	Early Sprite	Final Sprite	Notes
Charmander			Similar sprite, albeit with a different facial expression, and some missing detailing. This early sprite is directly based on this artwork of Charmander from the original series anime, whereas the final sprite made it more unique.
Caterpie			Totally different sprite, which is based on this artwork of Caterpie, whereas the final sprite instead used this one as a base.
Butterfree			Similar sprite, albeit with less dynamically posed feet, a narrower body and face, and a slightly less refined left eye and mouth. This early sprite is directly based on this artwork of Butterfree, whereas the final sprite made it more unique.
Weedle			Similar sprite, albeit quite rougher and larger than the final one. Both based on the same piece of artwork.
Rattata			Totally different sprite, which is based on this artwork of Rattata, whereas the final sprite went with a unique pose.
Raticate			Totally different sprite, which is rather rough, and appears to be based on Ratticate's Red and Green artwork. The final sprite instead uses this artwork as a base.
Spearow			Totally different sprite, which is based on this artwork of Spearow, whereas the final sprite went with a unique pose.
Arcanine			Similar sprite, albeit flipped horizontally and less refined. Both based on the same artwork.
Farfetch'd			Similar sprite, albeit with less dynamically posed feet, and with Farfetch'd holding the leek in one of its wings, instead of with its beak. This early sprite is directly based on this artwork of Farfetch'd, whereas the final sprite made it more unique.
Dodrio			Sprite is almost identical to the final, aside from some of missing shading and detailing. Both are based on the same artwork.
Jolteon			Totally different sprite, which appears to be based on Jolteon's Red and Blue artwork, albeit with a different facial expression. The final sprite instead uses this artwork as a base but with a face reminiscent of the early sprite.

Scratchpad Files#

A set of .CBB files from the 2024 Game Freak data breach, found in HaveSomeFun__RandomFromBoxEnt under the pokemon yellow directory, which is split into two folders:

• The first is called "送信済み" (sent) and ranges from 1998/04/07 to 1998/06/03 according to file modified dates. Worth noting is that Zubat, Golbat, Magneton and Zapdos are also found within this listing, but weren't included in the table below due to them already being finalized.
• The second is called "更新" (update) and ranges from 1998/04/28 to 1998/06/05 according to file modified dates. Unique to this later folder are already-finalized Geodude, Graveler and Electabuzz sprites. All other sprites were finalized, aside from a few outliers, noted further down.

Pokémon Name	Early Sprite (送信済み)	Final Sprite	Notes
Ivysaur			Similar sprite, albeit flipped horizontally and less refined.
Venusaur			Sprite is almost identical to the final, aside from some of the detailing on the main body.
Wartortle			Totally different sprite, which is rather rough, and appears to be based on Wartortle's Red and Blue artwork.
Blastoise			Totally different sprite, which is rather rough, and is reminiscent of Blastoise's Red and Blue artwork.
Nidorino			Similar sprite, only less refined.
Nidoking			Totally different sprite, with Nidoking seen from the back, not unlike its early Capumon sprite funnily enough.
Meowth			Almost completely different sprite, with a smaller head and one paw raised, instead of having both arms crossed.
Persian			Sprite is almost identical to the final, aside from some of the detailing around the face area, and being flipped horizontally.
Poliwhirl			The main body is identical, but the legs were redrawn, and the right arm and eye were touched-up to balance the pose.
Poliwrath			Totally different sprite.
Kadabra			Sprite is almost identical to the final, aside from the head and some overall detailing, and being flipped horizontally.
Alakazam			Sprite is almost identical to the final, aside from some detailing around the shoulders and knees, and being flipped horizontally.
Golem			An unfinished Golem sprite. What's there is close to the final sprite, aside from the right arm being out-stretched instead of bent.
Magnemite			Sprite is almost identical to the final, aside from the position of the screws.
Shellder			Totally different sprite.
Gastly			Sprite is almost identical to the final, aside from a portion of the darker smoke shade.
Haunter			Similar sprite, albeit rougher, and flipped horizontally.
Gengar			Sprite is almost identical to the final, aside from some of the detailing.
Drowzee			Lacks shading, and has its head cocked in the opposite direction.
Hypno			Sprite is almost identical to the final, aside from a missing ear and some detailing.
Kingler			Similar sprite, albeit rougher, and flipped horizontally.
Voltorb			Sprite is almost identical to the final, aside from some of the detailing.
Electrode			Sprite is almost identical to the final, aside from the angle of the face.
Exeggcute			Sprite is similar to final, only rougher, and with the central egg being smaller. The sprite is also flipped horizontally.
Hitmonlee			Similar sprite, albeit rougher, and flipped horizontally.
Hitmonchan			Similar sprite, albeit rougher, and flipped horizontally.
Rhydon			Similar sprite, albeit rougher, and with a slightly different pose.
Horsea			Sprite is almost identical to the final, aside from some of the detailing, and being flipped horizontally.
Starmie			Sprite is almost identical to the final, aside from some of the detailing.
Scyther			Totally different sprite, which is very hard to read.
Magmar			Similar sprite, albeit rougher.
Gyarados			Totally different sprite, which is harder to read, and is reminiscent of Gyarados' Red and Blue artwork.
Ditto			Similar sprite, albeit quite larger than the final one. The early sprite is directly based on this Ditto artwork.

Every sprite in "update" is finalized, aside from Venusaur (unchanged from "sent"), and the following three Pokémon (which are close to final).

Pokémon Name	Later Sprite (更新)	Final Sprite	Notes
Exeggcute			The right eye's pupil was shifted by one pixel.
Rhydon			The base of the tail was very slightly tweaked.
Gyarados			One black pixel in the left eye was replaced with light grey.

Early	Final

For some reason Abra's sprite in "sent" (dated 1998/04/28) is finalized, but the version in "update" (dated 1998/05/30) has a noticeably rougher head and different torso detailing.

Yellow Source Files#

These sprites, meanwhile, were found within the Yellow source code leak:

Early	Final

An early sprite of Pikachu, which is more directly based on this artwork from the original anime series. Labeled here as PMYF_DMY.DAT (the used sprite instead known as PMYF_025.DAT), likely standing for "Pokémon Yellow Front Dummy", this was likely just a scrapped early sprite the devs decided to keep for some reason.

Early	Final

Separate sprites for Jessie and James, found, respectively, under ROCKET1.DAT and ROCKET2.DAT. The final game instead combined them into a single sprite, known as ROCKETS.DAT. This, coupled with leftover trainer data and code, suggests that Jessie and James were meant to be fought individually. The sprites are nearly identical to the final, with only a straighter leaf on James' rose; Jessie's left eye has one less pixel, while the heel of her back leg is angled further out.

A cropped sprite of Magby's early design from Gold and Silvers Spaceworld '97 demo. Given how it is known asTEST.DAT', it was likely used as some sort of placeholder.

A sprite of Nidoran taken from the old official Game Freak website, down to using the same filename, 029NIDO.GIF. Likely used as reference for Nidoran♀'s updated sprite.

Sounds#

(Headphone warning: these audio clips are loud and harsh!)

Found in the SOUND folder of the leaked source code. As it turns out, 74 of the original 151 Pokémon had their Japanese anime cries or sound effects digitized, but none of them made it into the final game besides Pikachu's. This is likely due to the poor quality of the converted clips, the fact many of them are harsh on the ears, and the lack of space to fit them all in. Moreover, since many Pokémon have different names and/or cries between languages, this also means they'd need different voice clips for all the languages they wanted to release Yellow in.

Small wonder the idea was scrapped!

Pokédex 001-050#

Pokédex 051-100#

Pokédex 101-151#

Title Screen Mockup#

Hidden in /yellow/Document/pika.bmp is a mockup image of the English Pokémon Yellow title screen. Pikachu's sprite, while blocky, appears to have been scaled through an algorithm other than nearest neighbor, as color blending can be seen along its edges.