Carvanha

You may cast Carvanha from your graveyard if
you sacrifice a creature in addition to paying its
mana cost to cast it.
Devour 1 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters
the battlefield with that many +1/+1 counters on it.)
Protection from Wizards.
Frenzy 1 (Whenever this creature attacks and isn't
blocked, it gets +1/+0 until end of turn.)
Whenever a creature attacks or blocks Carvanha,
that creature gets -0/-1 until end of