|Ruler|| Hunson Abadeer
|Known characters||Hunson Abadeer|
|Introduced in||"It Came from the Nightosphere"|
|Latest appearance||"The Suitor"|
The Demons are a species who first appeared in "It Came from the Nightosphere." The only demon who appeared in the episode was Hunson Abadeer, who is Marceline's dad. The other Demons appeared in "Return to the Nightosphere," when Finn and Jake were exploring the Nightosphere. Most of them look completely different from one another. They look different from the traditional demon on the inside, though. Some of them are friendly, and others are very serious and strict. Only a few are truly evil.
- Hunson Abadeer
- Blood Demon
- Nightosphere Jailer
- The Teller
- Half Monster Demon
- Big Demon
- Ab Demon
- Boat Demon
- Line Demon
- Weird Punishment Demon
- Marceline (temporarily, until she became the Vampire Queen)
- Finn (temporarily)
- Farmworld Marceline (half demon)
- Marshall Lee (fictional, half demon)
- They were first mentioned at Wondercon 2012.
- Most of them were designed by Andy Ristaino.
- The demons in the Nightosphere excrete bananas from various orifices.
- It is shown that Demons do have a little hatred to the rules of the Nightosphere.
- There may be different 'species' of demons as most are different in appearance, but a few are very similar, such as Charlotte and her father.