Essence of ether

inhaled (toxin) - 300 gp
ToxinA creature subjected to this poison must succeed on a DC 15 Constitution saving throw or become poisoned for 8 hours. The poisoned creature is unconscious. The creature wakes up if it takes damage or if another creature takes an action to shake it awake.
Dungeon Master´s Guide
  1. DnD 5e Poisons › Essence of ether