The Wyvern is a highly sought-after massive flying dragon that can overpower most creatures it faces. Poison : Injury, Fortitude DC 17, initial and secondary damage 2d6 Con. A creature subjected to this poison must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one. Poison This poison must be harvested from a dead or incapacitated wyvern. On a successful save, the creature takes half damage and isn’t poisoned. poison damage and the target must make a DC 11 Constitution saving throw or be poisoned until the end of the wyvern’s next turn. Wyvern poison 5e Gamemastering >Monsters & Foes >Monsters By Type >Beasts >.