It's been a while since I did some mythical creature research. I'll be getting back to it. The things I discover inspire my stories. I hope they'll inspire yours.
For those who watch anime, there are some words used so often you don't need subtitles to understand their meaning. Shinigami is one of those words. This...being shows up a lot in anime. I was surprised how little information there was about them.
Shinigami only ensures that the individual dies, it does not perform any of the killing itself. Like most spirits associated with death, Shinigami have a reputation for being dark and malicious. It is also said that they are normally invisible to people, but can be seen by those for whom death is near. Shinigami sit on the border between life and death.
While their role in folklore has only come about in relatively recent times, the Shinigami’s impact on modern Japanese pop culture has been tremendous. From Bleach to Death Note, Shinigami are often portrayed as alternatively scary, monstrous beings to human-like entities merely fulfilling a function.
It's interesting how cultures influence each other. Remember that when you're world building.