Saryth, the Viper's Fang is a rare Legendary Creature — Human Warlock card from Innistrad: Double Feature (DBL), collector number 197. Current market price: $3.23 (foil $20.48), TCGplayer market prices via Scryfall.
Other tapped creatures you control have deathtouch. Other untapped creatures you control have hexproof. {1}, {T}: Untap another target creature or land you control.