Gelatinize

As an additional cost to cast Gelatinize, sacrifice
a creature.
Create a 0/0 green Ooze creature token. It
enters the battlefield with X +1/+1 counters on
it, where X is twice the number of counters on
the sacrificed creature.
Whenever three or more oozes you control die,
you may return Gelatinize from your graveyard
to your hand.