Sliver Overlord is a mythic Legendary Creature — Sliver Mutant card from Secret Lair Drop (SLD), collector number 10. Current market price: — (foil $33.17), 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.)