Caterpie

Caterpie (キャタピー Caterpie) is a -type Pokémon that can evolve into Metapod at level 7 and then Butterfree at level 10.

Appearance
Caterpie is a worm-like Pokémon that is mainly green in color with a tan underside. Just below its head are four tiny legs that are used only for movement. On top of its head is a red, "y-shaped" antenna, which can be used to produce an odor used in self-defense, in case something tries to hurt it.

Special abilities
Caterpie has the ability Shield Dust, which negates all status effects that are side effects of other moves. When threatened, it can release a strong odor from its antenna, which it uses to ward off predators.

In the anime series
Though Caterpie has quite a few cameos, the only time one of the main characters owned one was when Ash had a caught a Caterpie in the episode Ash Catches a Pokémon, being the first Pokémon he ever caught. During the same episode, Caterpie evolved into a Metapod.

Origins
Caterpie's name appears to be based on catepillar while its species appears to be a catepillar evolving into a butterfly.

Trivia

 * Caterpie has suction pads (located at the bottom of its feet) that allow it to climb trees and other walls or slopes with ease.
 * Caterpie and Goldeen have the same cry.