Anger Shell
When an attack causes its HP to drop to half or less, the Pokémon gets angry. This lowers its Defense and Sp. Def stats but boosts its Attack, Sp. Atk, and Speed stats.
Pokémon with this ability1 Pokémon
FAQ
What does Anger Shell do?
When an attack causes its HP to drop to half or less, the Pokémon gets angry. This lowers its Defense and Sp. Def stats but boosts its Attack, Sp. Atk, and Speed stats.
Which Pokémon have Anger Shell?
1 Pokémon have it, e.g. Klawf.