Gelus

Gelus appears in a flashback when Rem explains how to kill a Shinigami. He is a small, doll-like Shinigami whose appearance suggests that he was poorly sewn together from mismatched fabric. He only has one eye, despite having two eye sockets.

In the flashback, Rem recalls Gelus watching over a younger Misa Amane in the human world. Knowing that it was Misa's final day, she watches with him. Having fallen in love with Misa, Gelus uses his Death Note to kill Misa's destined murderer, against Rem's protests. Gelus is reduced to a pile of dust as punishment for extending a human life, leaving behind only his Death Note. In the anime, he is shown to drop the pen and start crying, before his eye disappears and he disintegrates. Rem delivers his Death Note to Misa because it was her that he saved as she thinks that was his final wish. In the film, she simply drops it and it lands near Misa. He is voiced by Ken'ichi Matsuyama in Japanese and Michael Dobson in the English dub.

In the Japanese version of Death Note: How to Read 13 his name is romanized as Jealous (ジェラス, Jerasu). In the English version of Death Note his name is romanized as Gelus.

Conception and development of Gelus
Obata said that Gelus appeared to be "a really beautiful" Shinigami in the thumbnails but decided to use his concept instead; Obata designed Gelus with a patchwork body since Gelus is a "really pitiful character." Obata added the trait of Gelus having difficulty writing names into the Death Note. Obata said that he believed that readers could relate to him and sympathize with him more if he looked "pathetic" and "stupid" instead of "beautiful."

He also said that at first he placed "detailed patterns" on Gelus' Death Note. When deciding that the patterns looked "too pretty" Obata covered the patterns with black, leaving the white portions visible. The text of the notebook is in a "Shinigami language."

Trivia

 * In the Japanese dub of the Anime, he is voiced by Kenichi Matsuyama - also known for playing L in the Deathnote film franchise.
 * His name is actually "Jealous," it was misspelled in the English manga, and it was not until the 13th manga was released, that we learn that his name had been misspelled