Venusaur

Venusaur is the final stage in the evolution of Bulbasaur. The plant on Venusaur's back blooms when it is absorbing solar energy and it is constantly moving to seek sunlight. In "Island of the Giant Pokemon," Ash and the gang wind up stranded on an island... but all of their Pokemon are missing. Pikachu, Squirtle, Bulbasaur, Charmander and the rest have their own adventure trying to get back to Ash, Misty and Brock. During their travels they run into a monstrous robotic Venusaur!

First appearance: Episode 17—"Island of the Giant Pokemon"