Generation Viii
Cotton Down
When the Pokémon is hit by an attack, it scatters cotton fluff around and lowers the Speed stat of all Pokémon except itself.
Detailed Effect
When the Pokémon is hit by an attack, it scatters cotton fluff around and lowers the Speed stats of all Pokémon except itself.
Pokémon With Cotton Down
2 canonical Pokémon forms can have this Ability.

Gossifleur
Eldegoss