Ghelmer was a powerful demon with the ability to fuse with, become and manipulate water at will, he uses these powers when assisting the demoness Sirene working alongside Agwel. He was one of the more famous demons from the TV series, he also had a counterpart in the anime going by the name of Geruge.
- Ghelmer (Manga): Ghelmer was a powerful demon with the ability to manipulate water at will, he attempts to kill Akira Fudo, however it is later revealed his part was only a distraction.
- Ghelmer (OVA): Following the same plot as his original appearance, Ghelmer now has an appearance resembling a preying mantis.
- Ghelmer (Grimoire): A demon who merged with the scientist Senda Mari, she later works with the demon Ebain to try and take down Amon.
- Ghelmer (CB Chara): A demon who kidnaps Miki Makimura. He lived with Sirene.
- Ghelmer (Devilman VS Getter Robo): A demon who worked for Sirene's army, he has his head ripped off by Akira.