Big Tuna, The Undying

Big Tuna, The Undying enters the battlefield
with a number of +1/+1 counters on it equal to
the amount of mana used to cast it.
If damage would be dealt to a creature while it
has a +1/+1 counter on it, you may prevent that
damage and remove that many +1/+1 counters
from Big Tuna, The Undying.
{u}{g}{r}: Place a +1/+1 counter on target
creature you control.