In Greek mythology, the Shirt of Nessus (also known as Tunic of Nessus or Nessus-robe) was an special poisoned shirt that caused the death of Heracles.
Metaphorically, it represents "a source of misfortune from which there is no escape; a fatal present; anything that wounds the susceptibilities"[1] or a "destructive or expiatory force or influence".[2]