Ahn Nubis the Dreamwalker

Indestructible
As long as your graveyard has less than five
creature cards in it, Ahn Nubis the Dreamwalker
isn't a creature.
Whenever a creature you control deals combat
damage to a player, Ahn Nubis the Dreamwalker
deals damage to that player and the attacking
creature equal to the amount of mana in your
mana pool.