Become the Avalanche is a rare Sorcery card from Tarkir: Dragonstorm Commander (TDC), collector number 43. Current market price: $0.31, TCGplayer market prices via Scryfall.
Draw a card for each creature you control with power 4 or greater. Then creatures you control get +X/+X until end of turn, where X is the number of cards in your hand.