Death has a human form, which is what he actually looks like. He just appears as a skeleton most of the time to scare people.

he should start using this form to scare people cuz it got me

Shi who is only a skeleton from hell itself: Pathetic

D: you're just mad I'm better-looking than you.

Shi: *Looks at death* You should be glad you weren't raised by Diabolus in the depths of hell. You should be glad you had your caring parents

Life looking at this being the only one born with actual flesh: I like both! Not really shi, but i like both!

dude we have the same parents
I never met our parents either, or at least I don't remember them.
I pretty much raised Life myself, until I met you!

Notes:
1. He looks kinda sad bc Death is kinda depressed by having to be the incarnation of Death itself.
2. which form he's in depends on his hood. (Up = Skelly, Down = Hooman)

Life: I never saw you like this brother!

Meanwhile my death literally be straight calcium