Multiple unreleased 2nd generation Pokemon have been discovered, including never-used baby forms and evolutions, different starter Pokemon, and other entirely abandoned concepts.
A recently uploaded ROM of the 1997 Nintendo Spaceworld demo for Pokemon Gold and Silver has been unpacked by fans at The Cutting Room Floor. The demo pre-dates the final version of the game by two years – and a lot seems to have changed in that time.
Most notable are the Pokemon themselves. For instance, the Cyndaquil and Totodile starters and their evolutions didn’t exist at this point – instead, they were Flambear and Cruz: