Sliver Overlord is a mythic Legendary Creature — Sliver Mutant card from Premium Deck Series: Slivers (H09), collector number 24. Current market price: — (foil $36.43), TCGplayer market prices via Scryfall.
{3}: Search your library for a Sliver card, reveal that card, put it into your hand, then shuffle. {3}: Gain control of target Sliver. (This effect lasts indefinitely.)