Doubling Season is a mythic Enchantment card from Battlebond (BBD), collector number 195. Current market price: $36.10 (foil $50.22), TCGplayer market prices via Scryfall.
If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead. If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.