Crab Monument

Whenever a non-token creature enters the battlefield, you may pay {p/u}{p/u}. If you do,
place a crab counter on it. (If a crab counter
is on a creature, it becomes a crab in adition to
it's other types and gains "Sacrifice this creature: Make a food Token.") Then, make a 0/3 Blue Crab token.
When all are crabs, all are food.