At the beginning of your upkeep, you may remove a counter from a permanent you control. If you don't, sacrifice this creature.
Mooo.
Illustrated by Randy Gallegos · Unglued · #63
There are no rulings for Hungry Hungry Heifer.
At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.
, Sacrifice a Saproling: Draw a card.
At the beginning of your upkeep, remove a -1/-1 counter from each creature you control.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)
At the beginning of each end step, if a +1/+1 counter was put on a permanent under your control this turn, put a +1/+1 counter on this creature.
Sacrifice a Saproling: This creature gets +1/+2 until end of turn.
Sacrifice a Saproling: You gain 2 life.
At the beginning of your upkeep, put a +1/+1 counter on this creature for each card in your hand, then remove a +1/+1 counter from this creature for each card in target opponent's hand.