Nekroth, The Endless Maw

Deathtouch

Whenever Nekroth, deals combat damage to a player, you may exile a creature card from a graveyard. If you do, put a +1/+1 counter on Nekroth, The Endless Maw.

Once per turn, you may play a card exiled this way for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast it.