Immunity() is a Pokémon ability introduced in the third generation.
Description
The ability holder cannot become poisoned. If the Pokémon got poisoned (either getting Poisoned before the ability was given to them or getting hit by a poison-afflicting move from a Pokémon with Mold Breaker), they get cured once their turn starts. The Pokémon consumes its Pecha Berry or other Poison-healing held item before Immunity activates.
From the fifth generation onwards as well as the third generation, if a poisoned Pokémon originally had Immunity but, currently does not, it will not heal its poison.
Outside of Battle
If the ability holder somehow got poisoned, they will not take poison damage. Battle Frontier events that poison won't poison this Pokémon.
Pokémon with the Ability
As a Hidden Ability
Trivia