I know you're getting sick of hearing me talk about them, but Death is also one of the beings created out of the Big Bang. It gets really confusing because some of them are sisters, while others are just random dudes like Galactus. I told you, you might have to do further research. This character is basically the living embodiment of Death, except she doesn't go around and choose every single person who dies. That's too hard of a job. It's like being the sad version of Santa Claus.
Death is generally portrayed as a female skeleton in a dark hood, though she can take many forms. When you're born from the Big Bang, you can pull off any look, in my opinion. The funny thing is that Thanos got the hots for her and tried to kill half the universe just to get with her. Some dudes will do anything for some tail.