Clay Champion is a mythic Artifact Creature — Construct card from The Brothers' War Promos (PBRO), collector number 230p. Current market price: $0.50 (foil $3.96), TCGplayer market prices via Scryfall.
This creature enters with three +1/+1 counters on it for each {G}{G} spent to cast it. When this creature enters, choose up to two other target creatures you control. For each {W}{W} spent to cast this creature, put a +1/+1 counter on each of them.