Owlbear Cub is a rare Creature — Bird Bear card from Battle for Baldur's Gate Promos (PCLB), collector number 246s. Current market price: — (foil $3.18), TCGplayer market prices via Scryfall.
Mama's Coming — Whenever this creature attacks a player who controls eight or more lands, look at the top eight cards of your library. You may put a creature card from among them onto the battlefield tapped and attacking that player. Put the rest on the bottom of your library in a random order.