Creation Engine

Sacrifice 4 permanents with different colors:
Cast a spell from your hand without paying its
mana cost if its none of those colors.
{b}{t}: Make a 1/1 Black Rat with Menace.
{u}{1}{t}: Make a 2/2 Blue Bird with Flying.
{w}{2}{t}: Make a 3/3 White Cat with Lifelink.
{r}{3}{t}: Make a 4/4 Red Monkey with Haste.
{g}{4}{t}: Make a 5/5 Green Bear with Trample.