Metapod is a Pokémon that resembles a green chrysalis. Its body is crescent-shaped with several segments making up the lower point. The front of Metapod's shell resembles a face with heavy-lidded eyes and a sharply pointed nose. The back of its shell consists of several geometrically shaped portions and projections.
Metapod's soft body is protected by a hard outer shell while it undergoes metamorphosis. While this shell is said to be as hard as steel, a sudden, powerful impact could cause its liquid innards to pop out, leaving it completely exposed. Metapod generally remains motionless, rebuilding its cells for evolution. If an enemy discovers Metapod, it is unable to do anything other than harden its outer shell. Metapod lives in temperate forests and jungles. Pikipek is a natural predator of Metapod.
Metapod also appeared in I Choose You!, which is set in a different continuity from the main series. It evolved from Caterpie during a battle against Pinsir and later evolved into Butterfree after a battle against Primeape.
In Caterpie's Big Dilemma, Zander's Caterpie evolved into a Metapod. It knocked down part of a radio tower so it could have a place to evolve at all, having become giant after eating some enhanced Rare Candies. It later evolved again to become a Butterfree.
In Butterfree and Me!, multiple Metapod evolved into Butterfree on Wayfarer Island. One Metapod had been befriended by Ash as a Caterpie, and Ash helped it eventually evolve into Butterfree.
In File 1: Red, a Metapod was seen in Professor Oak's introduction, while another was under the ownership of Red. Red sent out Metapod during his Gym battle with Brock, where it was able to slow Onix down with String Shot but was defeated afterwards.
Due to this, it was impossible to complete a Generation I game using only Caterpie or Metapod since Struggle could not hit Ghost types at the time.
Metapod is usually depicted with white sclerae, such as in the games, TCG, and promotional illustrations, but it has yellow sclerae in the anime.
In the anime episode Challenge of the Samurai, the process of Metapod's evolution was similar to a real life butterfly emerging from its chrysalis. In laterepisodes, however, Metapod is shown to evolve like any other Pokémon.
Ume Aoki, a Japanese cartoonist famous for her work on the manga Hidamari Sketch and as the character designer for the anime Puella Magi Madoka Magica, utilizes a likeness of herself cosplaying as a Metapod to represent herself in her works.
In the Space World '97 Super Game Boy demo version of Pokémon Gold, Metapod has a unique orange sprite that is exclusive to the demo.