Sidisi, Brood Tyrant is a mythic Legendary Creature — Snake Shaman card from Khans of Tarkir Promos (PKTK), collector number 199s. Current market price: — (foil $21.16), TCGplayer market prices via Scryfall.
Whenever Sidisi enters or attacks, mill three cards. Whenever one or more creature cards are put into your graveyard from your library, create a 2/2 black Zombie creature token.