Rotcepsni Thumb
Biographical information
Other names The Fiery One
Titles Demon Ruler of Hell
Birth Unknown
Death 25 December 2008 (later resurrected)
Weapons Demon powers, Magical abilities
Physical description
Species Kharmanorian Demon
Gender Male
Height 2.50m
Eye color Yellow, orange
Hair color None
Skin color Black
Chronological and political information
  • Demon Ruler of Hell
  • Destroyer of Hell Mockers
  • None

Rotcepsni is a demon who first appeared in CaptainsPlums' YouTube Poop, "Michael Rosen's Fiery Halloween", in which Rotcepsni attacks Michael Rosen and friends because of their school project of hell.

The school teacher, Ms. Catdog, first mentioned Rotcepsni by telling the students that they "were in really big trouble" because "there was a demon called Rotcepsni from hell, and he was ABSOLUTELY FURIOUS about our [Michael Rosen and friends] project".

Rotcepsni first appeared after a giant monster truck ran over the school. He then appeared to Michael Rosen and friends and took Michael and his friend Trevor to Demon World in Hell, to kill them for mocking hell.

Rotcepsni left Michael Rosen behind, taking away Trevor, as Michael was killed by a demon not long after only for him to return through the "Fuck Michael Rosen Portal" with a mech suit, where he beat the demon until he and his mother just fell over and disappeared, struck by the demon-saving meteor.