Pokemon - episode 51 - 01 Jul, 1998

When Ash's Bulbasaur gets injured in a battle, it starts to feel and act different. Ash takes Bulbasaur to a Pokémon Center and is informed that Bulbasaur is just ready to evolve, coinciding with an evolution festival where Bulbasaur from around the region evolve into Ivysaur in the Mysterious Garden. Ash's Bulbasaur gets kidnapped by a group of Bulbasaur and taken to the festival against its will, but Bulbasaur refuses to evolve. When Team Rocket tries to kidnap the wild Ivysaur and their leader Venusaur, Bulbasaur masters Solar Beam to rescue the group. (Source: Wikipedia)