Ivy, Gleeful Spellthief is a rare Legendary Creature — Faerie Rogue card from Dominaria United Promos (PDMU), collector number 201p. Current market price: $0.77 (foil $0.88), TCGplayer market prices via Scryfall.
Flying Whenever a player casts a spell that targets only a single creature other than Ivy, you may copy that spell. The copy targets Ivy. (A copy of an Aura spell becomes a token.)