Living infinitely long lifespan with immunity to aging and diseases.
Immortality is an infinitely long lifespan and an arrested aging process. So-called "immortals" can die but are immune to all kinds of human and supernatural diseases and viruses. Being immortal protects beings from dying a natural death through aging or disease. However, they can be killed by unnatural causes such as powerful magic, weapons, or powers.
It was mentioned that Mermaids cannot die unless they willingly give up their immortality. For this reason, they could be considered true immortals. Similarly, the Angels of Destiny and the Angel of Death are true immortals as well, as they play a vital part in the Grand Design. The demon of Fear, Barbas, could be considered a true immortal as well, as according to him "Fear never dies".
- Notable Individuals
- The skeletal being Necron was an undead demon. He needed to drain the life force of others to survive, proving that not all demons possess immortality.