Ice Face
The Pokémon’s ice head can take a physical attack as a substitute, but the attack also changes the Pokémon’s appearance. The ice will be restored when it snows.
Full effect
When an Eiscue that's in its Ice Face form is hit by a physical move, it takes no damage and changes into its Noice Face form. If a hailstorm or snowstorm begins while Eiscue is in its Noice Face form, or if it is sent out in its Noice Face form during hail, it will immediately revert to its Ice Face form.
In game description
The Pokémon's ice head can take a physical attack as a substitute, but the attack also changes the Pokémon's appearance. The ice will be restored when it snows.
Pokemon with Ice Face
Using Ice Face in Cobblemon
Abilities are passive and always active, so Ice Face 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.