Ravenous Squirrel is a uncommon Creature — Squirrel card from Bloomburrow Commander (BLC), collector number 258. Current market price: $0.33, TCGplayer market prices via Scryfall.
Whenever you sacrifice an artifact or creature, put a +1/+1 counter on this creature. {1}{B}{G}, Sacrifice an artifact or creature: You gain 1 life and draw a card.