Vizier of the Menagerie is a mythic Creature — Snake Cleric card from Amonkhet Promos (PAKH), collector number 192s. Current market price: — (foil $9.37), TCGplayer market prices via Scryfall.
You may look at the top card of your library any time. You may cast creature spells from the top of your library. You can spend mana of any type to cast creature spells.