Death (also distinguished as Mistress Death and Lady Death) is a fictional character appearing in American comic books published by Marvel Comics. The character is a cosmic entity based on the personification of death. The character first appeared in Captain Marvel #26 (Jun. 1973) and was created by Mike Friedrich and Jim Starlin.
Captain Marvel #26 (June 1973)
Mistress Death, Lady Death
Death’s Powers and abilities
Death is an abstract entity, possessing high infinite power and knowledge. The character occasionally appears as a humanoid female so as to be able to be perceived by lesser beings, and resides inside a pocket dimension known as the Realm of Death