Bramble Sovereign is a mythic Creature — Dryad card from Battle for Baldur's Gate Promos (PCLB), collector number 218s. Current market price: — (foil $4.47), TCGplayer market prices via Scryfall.
Whenever another nontoken creature enters, you may pay {1}{G}. If you do, that creature's controller creates a token that's a copy of that creature.