Armor Tail
Prevents the opponent from using any moves that have priority, such as Quick Attack.
Full effect
The mysterious tail covering the Pokémon’s head makes opponents unable to use priority moves against the Pokémon or its allies.
In game description
The mysterious tail covering the Pokémon's head makes opponents unable to use priority moves against the Pokémon or its allies.
Pokemon with Armor Tail
Using Armor Tail in Cobblemon
Abilities are passive and always active, so Armor Tail 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.