Darkrai

It can lull people to sleep and make them dream. It is active during nights of the new moon.

Darkness Roar (10): You may have your opponent switch the Defending Pokémon with 1 of his or her Benched Pokémon.

Sleep Hole (40+): If the Defending Pokémon is Asleep, this attack does 40 damage plus 40 more damage. If the Defending Pokémon is not Asleep, that Pokémon is now Asleep.