Thanatos is the God of Death, debuting in the original Kid Icarus under the name Tanatos.
Kid Icarus: Uprising - Idol Description (God of Death, Thanatos)
"The god of death. Bored with his 9-to-5 guiding the souls of the living to their final resting place, Thanatos turns his work over to the Reapers and leisurely passes his days in a palace deep beneath the ocean."
Kid Icarus: Uprising - Idol Description (Thanatos (Transformations 1))
"A talented shape-shifter, Thanatos takes various forms to fight. As a sword, the god of death is quick to stab, creating openings with his many points. When he transforms into a foot, a crushing stomp is sure to follow."
Kid Icarus: Uprising - Idol Description (Thanatos (Transformations 2))
"Thanatos's alternate forms give him dozens of unique attacks. Whether an urn, a bat, or a nesting doll, Thanatos's wild transformations are only to be underestimated by fools with a death wish."