Mimicry

Full effect

Changes the Pokémon’s type depending on the terrain.

In game description

Changes the Pokémon’s type depending on the terrain.

Using Mimicry in Cobblemon

Abilities are passive and always active, so Mimicry costs you nothing to run. If it is marked hidden on a species above, expect it to be harder to obtain: servers differ in whether hidden abilities come from breeding, an Ability Patch, or events.

See the Pokedex for which abilities each species can have, and IVs, EVs and breeding for how to actually pass one down.