Grudge is a PP-draining Ghost-type move.
When Grudge is used, if the user faints as the direct result of an attack, the move which causes the user to faint will lose all of its PP. This move's effect only works if the user faints before making another move. Grudge does not activate for damage that occurs at the end of the turn, including damage from Leech Seed, Toxic, Sandstorm, Hail, and Future Sight.
Pokémon that learn Grudge
By leveling up