ダムどん

Remnants of the previous demon king. Its official name is “Damned-Voval-Ambuschias." It is a being that only Akari can recognize, as she possesses the “Demon Core,” which is the proof of the Demon King. However, it is only within the Demon King's castle, and Damdon cannot leave the Demon King's castle. He teaches Akari his knowledge of the other world and the Demon King. He is the one who advised Akari to rely on Elfie and Almea, his former subordinates. He is a mere remnant of his former great power and appearance. His appearance is a mascot-like figure, a far cry from his former (before his death) self. [From official site]