Bulbasaurtwo is a clone of Bulbasaur and is the result of an experiment conducted by Dr. Fuji and a team of Team Rocket scientists.
Despite never gaining consciousness, Bulbasaurtwo managed to communicate with Bulbasaurtwo, Charmandertwo, Mewtwo and Ambertwo via telepathy.
Bulbasaurtwo enjoyed spending time in Ambertwo's "Remember Place" before suddenly dissapearing in front of Mewtwo and Ambertwo. This was because Bulbasaurtwo had perished in the experiment chamber in the real world.
(Bulbasaurtwo had markings over its body, which seems to mean it is a superior clone like the Vensusaur that Mewtwo cloned on New Island. Because Bulbasaurtwo can communicate using telepathy, this may mean that it has some kind of psychic ability.)