Biria, Rebel Centaur

+1: Add two mana of any color in Biria, Rebel Centaur's color identity.
-3: Put a 3/3 white red and green Centaur creature token with wither onto the battlefield.
-7: Shuffle in your library three events named Rebel Centaur Stampede that gives creatures you control trample and +3/+3 until end of turn.