Grace, Hawk's Shadow

{2}{t} Prey Upon (Put a prey counter on a creature
with "{2} Remove this counter: Until end of turn
this creature loses all abilities and is a 1/1 black
rat.)
Remove 3 prey counters: Exile target permanent
Whenever a prey counter is removed draw a card
Grace, Hawk's Shadow's power and toughness are
equal to the number of prey counters on the battlefield.