The Devourer

Deathtouch, Lifelink, Menace

When this creature enters, exile target creature or planeswalker from a graveyard. Put X +1/+1 counters on this creature where X is the total mana value of that permanent.
Whenever another creature or planeswalker dies, exile that permanent and put a number of +1/+1 counters on this creature equal to the total mana value of that permanent.