Overgrow

Overgrow (Japanese: しんりょく Fresh Greenery) is an ability introduced in Generation III. All of the Pokémon that have this ability are the -type Starter Pokémon from all regions, as well as Pansage and Simisage. In total, 17 Pokémon have this ability. Overgrow increases the holder's -type moves' damage, making them do 150% damage. However, this only happens when the Pokémon has 30% of its original HP remaining. Overgrow has no effect outside of battle.