Arbor Colossus is a rare Creature — Giant card from Commander 2015 (C15), collector number 174. Current market price: $0.17, TCGplayer market prices via Scryfall.
Reach {3}{G}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.) When this creature becomes monstrous, destroy target creature with flying an opponent controls.