Thanatos was the personification of Death in Greek myth; the god or daimon of non-violent death and the twin brother of Hypnos (Sleep). He is sometimes also considered to be a sibling of The Fates. Unlike other gods and supernatural beings of Greek myth, Thanatos could not be persuaded or placated.
In Roman depictions he held an inverted torch and sometimes a wreath of poppies or a butterfly (which represented the soul of the deceased). Early illustrations of the King in Yellow depict a figure holding an inverted torch in the manner of Thanatos and a symbol suggestive of an inverted torch has been suggested as an interpretation of the Yellow Sign.
Sigmund Freud theorised that humans have two principle drives; the death drive, Thanatos, and the life drive, Eros.