Shinigami (or Death Gods) are creatures similar to demons. Only, these beings judge wheather a man/woman should live or die. They keep a speacial book in which there are written speacial names of the people. To annihilate the humans, Shinigami use a Death Scythe.
Also, all of the shinigami have yellowish-green eyes, and are very near sighted.
Because of that, many shinigami need to wear glasses.