Feed the Pack is a rare Enchantment card from Dark Ascension (DKA), collector number 114. Current market price: $0.44 (foil $1.77), TCGplayer market prices via Scryfall.
At the beginning of your end step, you may sacrifice a nontoken creature. If you do, create X 2/2 green Wolf creature tokens, where X is the sacrificed creature's toughness.