Ash's Butterfree (Tom's Version)

Ash's Butterfree (Japanese: サトシのバタフリー Satoshi's Butterfree) is the fourth Pokémon that Ash Ketchum caught in the Kanto region.

Kanto
Caterpie first appeared at the end of Pokémon Emergency, staring at the group as they passed by. When Misty freaked out about its type and told Ash to do something, Ash pulled out a Poké Ball and threw it at Caterpie, hoping to catch it. In the next episode, Ash managed to catch the Worm Pokémon, being the first wild Pokémon he ever caught. Ash remarkably caught him without a Pokémon battle, which Misty attributed to Caterpie's weakness. Caterpie was quite fond of Misty, but, much to Caterpie's misfortune, she wanted nothing to do with him because it was a Bug-type Pokémon, which she feared. At night, Caterpie and Ash's Pikachu talked to each other, and Caterpie revealed its desire to evolve into a Butterfree. It became very sad as if it was not sure it could do it, but Pikachu encouraged it.

The next day, Caterpie was the first Pokémon Ash sent out against the next Pokémon he tried to capture, Pidgeotto. With a large disadvantage against the Flying-type Pokémon, it was beaten severely and was quickly substituted for Pikachu. Later, when Jessie, James, and Meowth appeared to attempt to steal Pikachu, Ash sent out his weakened Caterpie against them after they had blinded Pikachu and defeated Pidgeotto. Despite being made fun of by Team Rocket, it managed to take down both James's Koffing and Jessie's Ekans by using String Shot and Tackle, causing Team Rocket to run away. Just as Misty was about to get over her fear and congratulate Caterpie on its victory, it suddenly evolved into Metapod, which bothered her even more.

In Challenge of the Samurai, Metapod was sent out in a battle against Samurai. Despite only being able to use Harden, it managed to defeat his Pinsir by solidifying so much that the Stag Beetle Pokémon's pincers broke. Samurai then decided to send his own Metapod out against Ash's. Neither, however, could attack, and both had to sit stationary and keep hardening. The battle was then interrupted by a swarm of Beedrill that snatched Ash's Metapod away when he forgot to pick it up before running off. Ash felt guilty about this and became determined to get his Metapod back, finding it with a hive of Kakuna. Team Rocket showed up and woke up the whole hive of Beedrill with their motto, giving Ash a chance to rescue his Metapod. Metapod, however, was unhappy with Ash, but the Trainer tried to make an excuse and claim he didn't abandon Metapod. When Ash tripped on a rock and dropped Metapod, he owned up to his mistake and swore to never leave his Pokémon behind again. Metapod was moved by this and, seeing a Beedrill about to attack Ash, leaped up and took the blow, breaking the Beedrill's stinger and getting a large gash in its shell. Metapod then evolved into Butterfree and stopped all the Beedrill with its Sleep Powder attack.

In The Water Flowers of Cerulean City, Butterfree was used in Ash's Cerulean Gym battle against Misty, where it faced her Staryu. Butterfree managed to hit Staryu with Tackle and then dodged Staryu's. As Staryu landed, it lost its balance, giving Butterfree the chance to hit it with two more Tackles. Staryu then scored a hit with Water Gun and kept firing off the attack. Butterfree, however, dodged them all and crippled Staryu with Stun Spore. Misty had Staryu jump into the water to wash the spores off. When Butterfree went for Sleep Powder, Staryu dodged it by jumping into the water and kept using Tackle from underwater. Butterfree was then hit by another Tackle, knocking it into the water. As Butterfree was unable to swim, Ash was forced to concede the round and recall Butterfree to the safety of its Poké Ball.

Personality and Characteristics
As a Caterpie, it had a very happy but shy attitude, shown to suffer from low self-esteem if it didn't make a good first impression. He was very hurt when Misty didn't take to it. It was also very brave, squaring up against a Pidgeotto and then both of Team Rocket's Pokémon single-handedly. Its personality mellowed as a Metapod, becoming very laidback, but remained extremely loyal to its Trainer, jumping in front of a Beedrill to save him. As Butterfree, its personality was similar to that of Caterpie, retaining its bravery and positive attitude.