grave monster

(x is equal to the number of creature cards in your grave yard as well as the mana paid)
Grave monster enters the battle field with x +1+1 counters on it
:sacrifice a creatures in your grave yard put a +1+1 counter on
Grave monster
{t} remove any number +1+1 counters from Grave monster
create that many 1/1 black skeleton creature
tokens with death touch