In Grass Hysteria!, May was kidnapped by a hungry Skarmory and ended up lost in a reserve for Grass-typePokémon called the Forbidden Forest. There, she met a clumsy Bulbasaur trying to pick flowers. Bulbasaur warmed up to May after being saved from a fall, but the other Pokémon in the reserve repeatedly tried to attack May. However, Bulbasaur explained to Venusaur, her parent and the ruler of the Forbidden Forest, that May was a friend. Before May had to leave, Bulbasaur decided to stay with her.
In Hokey Poké Balls!, May sent out her Bulbasaur to enjoy the sights as they went through a city. Bulbasaur quickly gets distracted by some flowers in a truck and has to be rescued as the truck speed off. Later at the Pokémon Center May shows Professor Oak her Bulbasaur, which makes Ash decide to bring his Bulbasaur over for a visit. When the Poké Ball arrives though it won't open, making everyone believe that the Pokémon Center's balls were stolen. It is revealed to be Team Rocket, who accidentally drop Ash's Bulbasaur while escaping. The two Bulbasaur team up to stop Team Rocket, with Ash's Bulbasaur teaching May's along the way. Once they find Team Rocket the Bulbasaurs battle against them, with Ash's Bulbasaur protecting and teaching May's how to fight. After rescuing the Pokémon Professor Oak calls back and asks for Ash's Bulbasaur to return and stop the water and grass Pokémon from fighting. Ash sends his Bulbasaur back to Professor Oak's Laboratory as May's Bulbasaur appears to have made a positive change from the experience.
Bulbasaur also competed in the Battle Round of the Hoenn Grand Festival. In Rhapsody in Drew, she was called out to battle along with Beautifly against Harley's Cacturne and Banette. Together they managed to defeat their opponents and advance May to the next round.
Kanto Battle Frontier
In The Right Place and the Right Mime, Bulbasaur was shown to be one of the Pokémon May decided to bring with her when she traveled through the Kanto region. Bulbasaur reunited with Ash's Bulbasaur when May made a stop at Professor Oak's Lab to meet up with Ash. The two Bulbasaur were later used in a battle against Team Rocket, where May's Bulbasaur was impressed by Ash's Bulbasaur's skill. May decided to leave Bulbasaur at Professor Oak's Lab so she could learn more from Ash's Bulbasaur. Eventually, after journeying to the Johtoregion, May got Bulbasaur back from Professor Oak, and during her time away from Ash, she evolved twice, into Ivysaur and Venusaur.
She debuted as a Venusaur in Pruning a Passel of Pals!, where she defeated a Marill for May in the second battle round of the Wallace Cup. Not much is known about Venusaur since she only had a cameo appearance.
Personality and characteristics
With Ash's Bulbasaur
As a Bulbasaur, she proved to be a very sweet Pokémon. She was very willing to compete in Contests and do the best she could. She was very confident in most of her Contests. The only exception was her first Contest, in which her nervousness showed in her performance.
She was distinctive from Ash's Bulbasaur in three ways: she had a gentler personality, a pair of heart-shaped spots on her forehead and she was able to use the move Petal Dance as opposed to Ash's Bulbasaur's use of the technique Solar Beam.
It is unknown whether she still holds on to these traits after evolution.