Wondrous Item, legendary (requires attunement by a requires attunement by filling the vial with blood from unknown origins and ingesting one drop of the blood)
By ingesting a drop of the mystery blood, the player has resistance to all poisons and has advantage on all constitution saving throws for the next 24hrs.
Notes: Advantage: Constitution Saving Throws, Resistance: Poison, requires attunement by filling the vial with blood from unknown origins and ingesting one drop of the blood