Bitterblossom is a mythic Kindred Enchantment — Faerie card from Modern Masters 2015 (MM2), collector number 71. Current market price: $34.22 (foil $41.36), TCGplayer market prices via Scryfall.
At the beginning of your upkeep, you lose 1 life and create a 1/1 black Faerie Rogue creature token with flying.