Cryptomoeba

Cryptomoeba enters the battlefield with a
number of Plasm counters on it equal to the
number of creature cards in your graveyard.
When Cryptomoeba has no Plasm counters, sacrifice it.
Cryptomoeba gets +1/+1 for each Plasm counter
on it.
{2}{b}{g}: Return Cryptomoeba from the graveyard
to your hand.