Ivysaur is the second stage pf evolution for Bulbasaur. When the bulb on its back grows large, Ivysaur appears to lose the ability to stand on its hind legs. In “Bulbasaur and the Hidden Village”, Ash and company were treated to a wondrous surprise when they followed Bulbasaur to the Secret Garden of the Bulbasaur… The time of evolution was upon them. Every year, the wild Bulbasaur migrate to a hidden location in the wild to evolve to Ivysaur. Ash’s Bulbasaur was entranced, but decided that it did not want to evolve yet.
First appearance: Episode 51 — “Bulbasaur’s Secret Garden”