Merfolk Spy 
Creature — Merfolk Rogue
Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Whenever this creature deals combat damage to a player, that player reveals a card at random from their hand.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL