NOTE: Since writing this article, it has come out that the BETA Rom is very likely a fake. The designs in the BETA Rom are mostly taken from official Game Freak Prototype documents that have been posted on the internet by Game Freak staff, passed around the internet and redrawn for the rom - and are likely changed and slightly redesigned if the original image was unclear. Take all the information below with a grain of salt.
Nintendo Space World was a video game trade show that ran from 1989 to 2001 held around Japan to show off new video games and projects - Think E3, but focused heavily on Nintendo. As with all trade shows, they show of demos and unfinished products. One of the bigger games that was recently leaked online was the Pokémon Gold & Silver BETA which was originally only shown in a short video, or for those lucky enough to attend the event. Not only did this demo show off unreleased and unfinished Pokémon, It also had a new Map, new locations and a slightly different story. In mid 2018, the full BETA Rom was released online in both Japanese and translated English for fans to play through, with sprite sheets posted to show off all the unreleased Pokémon.
Very recently, streamer, Abra started a charity stream called Pokéthon and on a recent stream, showed off the previously unseen BETA for Pokémon Red & Green (Blue in the West). During the stream, some of the unreleased Pokémon shown off were Gaotora - a little tiger like Pokémon, Cryithan - a small lizard like creature, Pendraken - a giant squid, based off a Kraken and Maws - a hammerhead shark with a spear on it's nose... and that's only the tip of the iceberg.
Much like in the Gold & Silver BETA, the Red/Green/Blue BETA also had Baby Pokémon, some shared in both games. A few highlights are Charcolt - the pre-evolved form of Ponyta and Rapidash, Trixy - a baby variant of Vulpix and Ninetales, Coinya - a tiny Meowth and Persian (and one of the ones I personally wish they left in!) and Bittybat - the pre-evolved form of Zubat and Golbat.
It wasn't only Baby Pokémon that were shown off, but also some original evolutions, some that really change how the Pokémon Community will think of certain species. First up, before we get into the good stuff, we have Totartle - what seems to be a replacement for Blastoise. I'm glad they changed this one up, personally. Next up we have the mystical Gorochu - the fabled third evolution of Pikachu and Raichu. Gorochu was originally revealed by name from an interview with Atsuko Nishida, who worked as a graphic designer on the original games. Previously, all we heard about Gorochu is that it was cut out for balacing purposes - and that it has fangs and horns on it. We finally get to unmask the myth and see what could have been.
The last Pokémon in the evolution section I'll talk about it Guardia - who originally evolved from Cubone. Marowak (Cubone's current evolution) was originally called Guardia in very early press releases and with the strong resemblance to Kangaskhan, Guardia seems to confirm that Cubone's Mother might have originally been Kangaskhan with a split evolution into Guardia for the Male Cubone (much like female Snorunt into Froslass, male into Glalie).
The final few Pokémon I'll talk about will be the Pokémon that could have been. First up is Jabetta, who seems to have a strong resemblance to Oricorio (Gen VI), particularly the Sensu form, but this is all speculation. Jabetta seems to have been a fighting type - and was possibly a fish, it's rather hard to tell in sprite form. Bloonder takes heavy inspiration for Drifloon (Gen IV) with the same premise of them being a straight up balloon. At least Difloon was given more character in it's design. Croakozuna is an early prototype design for Politoed (Gen II) with all of the Poliwag line have drastic design changes over BETA to final release. I guess it was fitting that Croakozuna joins in with that. Decilla seems to look a lot like the Substitute Doll (from the Attack of the same name) but could also be a Larvitar (Gen II) BETA design, again, it's a bit hard to tell with sprites. Roardan may be the original name for Tyranitar (Gen II), who also showed up in a bit of promotional material for the original games, but it may also be another creature, unknown to us.
So many new Pokémon that I never mentioned were also shown, with sprite lists being made by Helix Chamber. If you would like to watch the stream, or follow along with Abra's progress, you can do so on the Pokéthon Website. A big thank you to YouTuber, Bird Keeper Toby for his screenshots of the stream and be sure to check out the Helix Chamber's Twitter for more documentation on the BETA Rom.
