Rubblehulk is a rare Creature — Elemental card from RNA Guild Kit (GK2), collector number 95. Current market price: $0.41, TCGplayer market prices via Scryfall.
Rubblehulk's power and toughness are each equal to the number of lands you control. Bloodrush — {1}{R}{G}, Discard this card: Target attacking creature gets +X/+X until end of turn, where X is the number of lands you control.