Metapod

Biology
Metapod have a very soft body, which makes them hide in a very hard shell upon evolution. Their shell is so hard that they automaticly improve a move called Harden, which makes them defensively stronger in the battle. However, because of their shell they hide in, they move very hardly and slowly. They are so shieldless and nonprotected in that form that, most of the species hide in the forests to prevent encountering a trainer, which makes them very rare to be found in the nature.

Behaviour
Because of their limited freedom of speed and move, they hide in the areas they can be found. As Pokédex states in, it is very rare for a trainer to encounter a wild Metapod in the nature as they are good at hiding themselves. When they are under the ownership of a trainer, they are usually kept outside of the battles until they evolve. This species evolves when their process of maturing is completed.

Habitat
No Metapod has been found or encountered as a wild Pokémon in the nature.

Greta's Metapod

 * Main Article: Metapod (Greta Parker)

In, Greta's Caterpie was called out to battle for Parasect Pack against Beedrill Pack in the Viridian Forest. After Gabor's Exeggutor defeated and, Caterpie was the only option Greta had. Since Caterpie was resistant to Exeggutor's Psychic type moves, his Psychic move did not effect Caterpie as expected. Caterpie used her usual tactic, and started the battle with String Shot to eleminate the speed of the foe. Afterwards, she attacked with Tackle by making a direct hit on him. After a couple of attacks, Exeggutor fainted which brought Caterpie a victory. Over her victory, the Parasect Pack was encouraged to battle for their spores. After Greta glorified Caterpie, she evolved into a Metapod by the proud of her moment.