Debo Akkumuun can block blasts with his Memory-Foam Shield, which is soft enough to absorb Gabutyra's charge and send him back flying once enlarged, make anyone fall asleep with his Restful Bomber, and attack with his Explosive Flame Bomber.
Thanks to Rin Katsuyama's special energy drink, Souji and the others were able to quickly defeat Debo Akkumoon with a Zyuden Brave Finish/Slash combo, then an enlarged Debo Akkumuun is quickly destroyed by the teamwork of Pteraiden-Oh, Plezu-Oh, and Kyoryuzin Stegotchi Zakutor.
- Height: 201 cm (50.3 m: giant)
- Weight: 147 kg (367.5 t: giant)
- Akkumoon's name is derived from the word "Nightmare".
- This is Luckyuro's first Debo Monster.