Hmm . . . well in my universe I have two death gods.
The first one is called The Great Forest King Naga. As his name implies, he is a white tailed naga and his forest is where spirits would rest. The second one is his spouse named Moose. He was a young child who wandered into the forest in order to look for a curative flower for his ill mother. Naga couldn't bare to kill Moose, but also could not let him go back to the human world because he was already tainted by the spirits. So Naga made a pact with Moose. Naga became the King of Death and Moose became the King of the Undead.
Most of the gods in my universe are based on animals, the the exception of The King of Undead and the Gods of Love and Sacrifice. I think they're just more interesting to look at and be creative with. (If you're confused about my naming terms, King is refers to the original old gods and God refers to the modern new gods, haha.)
You can always do research on the personification of Death from other cultures and draw inspiration from there.
- Greek had Thanatos, who was an attractive young man with wings or young boy. He was considered to be kind and gentle.
- In Celtic folklore, there was a figure named Ankou, who was kind of the local death spirit. They were the representation of the person who died recently, but taller. They looked either like a shadow or typical reaper with white hair or a wide hat and drove a cart or wagon full of corpses.
- Ireland had the dullahan, who were an entire species of headless horsemen/women. They would visit homes of people who were about to die, say their name, and the person would die. Dullahan hated being seen by human and lash at their eyes with a whip made of a spine. Ireland also had the banshee, which you may know is the wailing woman who heralds the death of a person.
- Scotland has the Cu-Sith, which was a huge, shaggy dog with green or white fur. They are the harbingers of death and would guide souls to the after life. They can hunt silently and will sometimes let out 3 howls. Those who hear these howls must reach safety or else they'll be overcome with crippling terror.
- East Anglia had the the Black Shuck, a large, ghostly, black dog with red eyes (sometime only one eye). They haunt coastlines, graveyards, sideroads, crossroads, bodies of water, and dark forests.
- Japan has he shinigami, who are gods or spirits that would to invite humans towards death. There's also the goddess of creation and death Izanami-no-Mikoto. She is often depicted as a woman with long black hair wearing a white kimono.
- In Korea, they have the Netherworld Emissary named Joeseung Saja. He is extremely pale with sunken eyes and wears long black robes with a tall, black hat.
This is all information that I got from just reading a wiki page, so the accuracy on some of these death figures may be dubious, but still pretty interesting.