Lunar Avenger is a uncommon Artifact Creature — Golem card from Fifth Dawn (5DN), collector number 136. Current market price: $0.10 (foil $1.69), TCGplayer market prices via Scryfall.
Sunburst (This creature enters with a +1/+1 counter on it for each color of mana spent to cast it.) Remove a +1/+1 counter from this creature: This creature gains your choice of flying, first strike, or haste until end of turn.