Blacksnout Cutthroat

You may exert Blacksnout Cutthroat as it attacks. If you do, destroy target creature blocking Blacksnout Cutthroat. (An exerted creature won't untap during your next untap step.)
Put the top card of your Library into your Graveyard: Untap Blacksnout Cutthroat.
A canine snout, but a snake's mind.