Garruk's Harbinger
Oracle Text
Hexproof from black
Whenever Garruk's Harbinger deals combat damage to a player or planeswalker, look at that many cards from the top of your library. You may reveal a creature or Garruk planeswalker card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
I would rather see something like "whenever this is targeted by a black spell controlled by your opponent get X".