Bulletproof
Protects against bullet, ball, and bomb-based moves.
In game description
Protects the Pokémon from ball and bomb moves.
Pokemon with Bulletproof
Using Bulletproof in Cobblemon
Abilities are passive and always active, so Bulletproof 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.