Waxmane Baku is a common Creature — Spirit card from Betrayers of Kamigawa (BOK), collector number 29. Current market price: $0.09 (foil $0.52), TCGplayer market prices via Scryfall.
Whenever you cast a Spirit or Arcane spell, you may put a ki counter on this creature. {1}, Remove X ki counters from this creature: Tap X target creatures.