Momir Vig, Simic Visionary is a rare Legendary Creature — Elf Wizard card from Dissension (DIS), collector number 118. Current market price: $2.54 (foil $11.63), TCGplayer market prices via Scryfall.
Whenever you cast a green creature spell, you may search your library for a creature card, reveal it, then shuffle and put that card on top. Whenever you cast a blue creature spell, reveal the top card of your library. If it's a creature card, put that card into your hand.