Ash's Bulbasaur/Personality & Characteristics

Bulbasaur is one of Ash's most mature Pokémon, and is frequently viewed as the responsible leader of Ash's Pokémon, especially due to its actions at both Melanie's Hidden Village and Professor Oak's lab. In Sick Daze, it showed that it had learned from its experiences by recognizing a trap that Ash's Johto starters could not.

Unlike its closest friend, the boisterous and immature, Bulbasaur was cautious bordering on cynical of all Trainers when it joined Ash's team, going so far as to physically attack Misty when it thought she was trying to take an Oddish away. In Island of the Giant Pokémon, it alone assumed that Ash had abandoned them. Its views on Trainers were presumably colored by all the abandoned Pokémon in the Hidden Village. Over time, Bulbasaur grew to trust its new Trainer, but it retained a stubborn, surly, and eager-to-battle demeanor. For example, in Bulbasaur's Mysterious Garden, it dodged Ash's call to return and insisted on finishing the battle. This hard personality was briefly softened during a visit to a garden full of exotic plants run by Florinda Showers, where Bulbasaur developed a certain affection for her, but nothing apparently came of it.

Although Bulbasaur is one of Ash's most mature Pokémon, it has succumbed to fits of immaturity when Squirtle is involved. This is seen multiple times in disagreements or quarrels between the two. In Christmas Night, after Squirtle accidentally eats Bulbasaur's Bulbasaur-shaped cookie, despite being apologetic, Bulbasaur still chases and attacks Squirtle. In Kanga Games, Pikachu, Togepi and a baby Kangaskhan ride past Bulbasaur and Squirtle on a sled. Eager to join in, Bulbasaur flips Squirtle onto its back and uses Squirtle as an involuntary makeshift sled.

Its biggest fear appears to be of its fully evolved form,, demonstrated in Island of the Giant Pokémon and The Ghost of Maiden's Peak, both times where it was paralyzed in fear by fake Venusaur. Interestingly enough, it defied the wishes of the first real Venusaur it encountered, demonstrating that Bulbasaur is a courageous Pokémon when standing up for something it believes in.