Mummy

Full effect

Whenever a contact move hits this Pokémon, the attacking Pokémon's ability changes to Mummy. Multitype is unaffected. If a Pokémon with Moxie knocks this Pokémon out, the former's ability will change without taking effect.

In game description

Contact with the Pokémon changes the attacker’s Ability to Mummy.

Using Mummy in Cobblemon

Abilities are passive and always active, so Mummy 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.