Death
One of the Endless, personifications of concepts required for the universe to exist. She is very likeable.
Where is she from?
Death and the rest of the Endless are creations of one Neil Gaiman, one of those rare human beings who is just a gift to the entire world. They are part of his comic opus, Sandman, a series that was published from 1989 to 1996, and is arguably the single greatest comic series ever put on paper. While there's been no live-action adaptation of the Sandman, Death herself appeared in a DC Showcase animated short where she was voiced by Jamie Chung. You can watch it right here:
Comic Appearances
GND 187 - Sarah, Christine & Luna see off Susan Sto Helit. She talks to her grandfather Death (and his horse Binky), who talks to Death of the Endless, who talks to her brother Morpheus, who then takes the Pale Man to the Nightmare Realms, where he can befriend the Corinthian & Matthew.