Poison Heal
Heals for 1/8 max HP after each turn when poisoned in place of damage.
Full effect
If this Pokémon is poisoned, it will heal for 1/8 of its maximum HP after each turn rather than taking damage. This includes bad poison.
In game description
If poisoned, the Pokémon has its HP restored instead of taking damage.
Pokemon with Poison Heal
Using Poison Heal in Cobblemon
Abilities are passive and always active, so Poison Heal 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.