Hypnox 
Creature — Nightmare Horror
Flying When this creature enters, if you cast it from your hand, exile all cards from target opponent's hand. When this creature leaves the battlefield, return the exiled cards to their owner's hand.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL