Primal Plasma is a common Creature — Elemental Shapeshifter card from Planar Chaos (PLC), collector number 59. Current market price: $0.08 (foil $0.23), TCGplayer market prices via Scryfall.
As this creature enters, it becomes your choice of a 3/3 creature, a 2/2 creature with flying, or a 1/6 creature with defender.