Hunson Abadeer

He is an embodiment of chaos and claims to be "completely evil" (these are later suggested to be effects of the Nightosphere amulet). He also shows appreciation for things he deems to be greatly evil; in "It Came from the Nightosphere," he comments that Gunter is the "most evil thing [he] has encountered" (foreshadowing Gunter's reveal as Orgalorg). Gunter, the Ice King, Jake and Finn were the only souls that were spared during his rampage through Ooo. In addition, Hunson Abadeer is shown to be rational, cold and calculating. However, he is not totally emotionless, as he appears to be deeply moved by hearing his daughter's song. He confirmed that he loves Marceline, and that he was deeply sorry he ate her fries, never meaning to hurt her. This incident seems to have altered his personality, as in "Return to the Nightosphere," he is far less evil than before even with the Nightosphere amulet on, with the implication that this change was because of his previous interaction with Marceline. While he is markedly 'nicer' than before, he may only be so to Marceline, Finn and Jake. In "Daddy's Little Monster," he was quick to act hostile toward Jake before realising it was him.

He is first shown exiting the Nightosphere as a mass of tentacles, eyeballs, intestines, and various other like appendages, but his usual form consists of a demon-like humanoid with a light blue skin tone, pointy ears, flat dark blue hair, a dark business suit and light yellow eyes with slit neon pink pupils. His face shows slightly more detail than most characters of the show; showing more cheek bone and eye definition than others. The inside of his mouth (aside from his purplish pink tongue) is green, with the hue of green getting slightly darker the closer to the back of the throat. He seems to lack a uvula and a defined chin. His movements are occasionally jerky and unnatural, moving with what appears to be additional or especially stiff but flexible joints. He has the ability to shapeshift, like his daughter, and has been seen with a second, monstrous head with a vertical mouth that usually hides inside his normal mouth at the back of his throat (an effect of the Nightosphere amulet). When he transforms into a large monster this monstrous head emerges from his throat and replaces his normal head. He wears a pair of red boots just like Marceline. However, without the Nightosphere Amulet, he sports a white tank-top, a pair of green-striped pink boxers, and has a slightly bulging belly that is hidden when he is wearing his suit.