Fresh from meeting Professor Oak for the first time and making Pikachu his first Pokémon, it wasn’t long before Ash wanted to practise his Pokémon capturing skills. As you will know, if you can’t catch wild Pokémon, you’re no one! In episode ‘Ash catches a Pokémon’, he set off into the Kanto region and the first Pokémon he encountered in the Viridian Forest was a Caterpie. Luckily for Ash this Pokémon was weak, and it was soon captured when Ash threw a Pokéball at it – there was no Pokémon battle needed.
The night after being captured, Caterpie revealed to Pikachu that he really wanted to evolve into a Butterfree, but that would first mean becoming a Metapod and Caterpie didn’t think he could do it. Pikachu encouraged him to try. In a battle with Team Rocket, Caterpie managed to evolve, then in ‘Challenge of the Samurai’ while attacking a Beedrill with his Sleep Powder he finally managed to achieve his ambition and evolved into a Butterfree, to Ash’s delight!