Enduring Vitality is a rare Enchantment Creature — Elk Glimmer card from Duskmourn: House of Horror Promos (PDSK), collector number 176p. Current market price: $18.04 (foil $15.79), TCGplayer market prices via Scryfall.
Vigilance Creatures you control have "{T}: Add one mana of any color." When Enduring Vitality dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)