Shield Dust
Protects against incoming moves' extra effects.
Full effect
This Pokémon is immune to the extra effects of moves used against it. An extra effect is a move's chance, listed as an "effect chance", to inflict a status ailment, cause a stat change, or make the target flinch in addition to the move's main effect. For example, Thunder Shock's paralysis is an extra effect, but Thunder Wave's is not, nor are Knock Off's item removal and Air Cutter's increased critical hit rate.
In game description
Protective dust shields the Pokémon from the additional effects of moves.
Pokemon with Shield Dust
Using Shield Dust in Cobblemon
Abilities are passive and always active, so Shield Dust 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.