Ogre Marauder

Creature - Ogre Warrior 3/1, 1BB (3)
Whenever Ogre Marauder attacks, it gains "Ogre Marauder can't be blocked" until end of turn unless defending player sacrifices a creature.¹
Once freed, the oni demanded more and more sacrifices to appease them. The ogres happily obliged.
Illus. Adam Rex

Gatherer Card Rulings [Nov 2009]

• 2/1/2005: Ogre Marauder's ability requires the defending player to sacrifice a creature as the ability resolves, or Ogre Marauder can't be blocked for the rest of the turn.
• 2/1/2005: Attacking with Ogre Marauder a second time would cause a second trigger. If no creature was previously sacrificed, the Marauder already can't be blocked. Sacrificing a creature for the second trigger will not nullify the first.

Format Legality	Legal in Vintage, Legacy, Extended, MTGO Classic Banned in Standard
Printings (1/8)	Betrayers of Kamigawa (Uncommon)