Empty the Warrens

Create a 4/4 green Beast creature token. Flashback 2GGG (You may cast this card from your graveyard for its flashback cost. Then exile it.)

1RG: This creature gets +1/+1 and gains trample until end of turn.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) Whenever this creature attacks, you may return target creature to its owner's hand if its power is less than this creature's power.

(T: Add G.)

Cowards can't block Warriors. R: Target creature becomes a Coward until end of turn. 2R: Target creature becomes a Warrior until end of turn.

(T: Add R.)

Draw a card.

When this creature enters, add RG.