Scans_Daily

If you've read the Incarnations of Immortality by Piers Anthony, it gives away a plausible explanation. It's our perception of who and what Death is that gives her a bony look outside of her "body" (her being an incarnation of a universal constant). Like an image-inducer or "perception field" from Dr. Who.

Asgardian Death Goddess Hela has opposite issue, with her cloak and outfit keeping her true rotting form hidden from view in the disguise of a beautiful goddess.

Underneath the Garments of her Office, Death has the body and mortal form she chooses (at this point something eye catching for her Paramour, Deadpool). No, no Bea Arthur.