Cheek Pouch
Restores HP upon eating a Berry, in addition to the Berry's effect.
In game description
The Pokémon's HP is restored when it eats any Berry, in addition to the Berry's usual effect.
Pokemon with Cheek Pouch
Using Cheek Pouch in Cobblemon
Abilities are passive and always active, so Cheek Pouch 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.