Brain Maggot 
Enchantment Creature — Insect
When this creature enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card until this creature leaves the battlefield.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL