Grothama, All-Devouring 
Legendary Creature — Wurm
Other creatures have "Whenever this creature attacks, you may have it fight Grothama, All-Devouring." When Grothama leaves the battlefield, each player draws cards equal to the amount of damage dealt to Grothama this turn by sources they controlled.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL