Millenniummon is a Mega Level Digimon. His physical appearance is a mixed form of both the overwhelming power possessed by Machinedramon and the data of various powerful Digimon possessed by Kimeramon. He appears as a grotesque beast with four long black claws, two huge long feet with red claws, Kimeramon's head and Machinedramon's Giga Cannons on its back. Also on its back is a strange fiery aura in a shape of a winged dragon-like creature that acts as some kind of skin coat like the one Gabumon has on him at all times.
It is said that Milleniummon is impossible to defeat, and at present the unclear cause of its fusion is being ascertained, but it is unlikely that any clues will be found.
Digimon Adventure: Anode/Cathode Tamer
Digimon Adventure 02
It made a cameo appearance of being defeated by Ryo and Ken in a flashback.
Digimon Adventure 02: Tag Tamers
Digimon Adventure 02: D-1 Tamers
Digimon Tamers: Brave Tamer
Digimon Xros Wars (Manga)
- Ultimate Fusion (Time Unlimited): Creates a pocket dimension with compressed time, and traps an opponent there for an eternity.
- Dimension Destroyer: Destroys the pocket dimension Milleniummon have created and anyone or anything that is trapped within.