Carnak, the megalodon

Whenever you cast Carnak, the megalodon, each
non-land permanent you control gets +2/+2.
Whenever Carnak, the megalodon attacks, put a
+1/+0 counter on target creature.
{2} Sacrifice target creature you control, Carnak,
the megalodon deals damage to any target equal
to the toughness of the sacrificed creature.