The Great Horned Rat

You may cast this card any time you could
cast an instant by sacrificing any number of
Rats and paying the difference in mana costs
between this and the sacrificed Rats. Mana cost
includes color.)
As long as your devotion to {b} is less than five,
The Great Hornet Rat isn't a creature.
When a Rat you control deals damage to an
opponent create a token that is a copy of that rat.