Cthulhumon is the main antoganist in Digimon Ultimate, alongside with Crimson Blood of Orchid team.
The name and design derive from the god Cthulhu. Cthulhumon is the Dark Gaurdian of the Digital World wile CyanAgumon is the Light Guardian. The first CDFC was a online phenomana were Crimson Blood (Who was assigned to Orchid team)Joined when she was asked for her Leader Digimon and DV6 model number (Later becomes DV7 after she wins CDFC)Wich is when Cthulhumon appeared on the moniter of her computer, Cthulhumon told her that Digimon and the Digital World and him are real as she is, and tells her if she becomes his Digimon partner then she could compete in CDFC, she agrees and recievs a blue camoflauged DV6 (Upgraded to DV7 after Crimson Blood won CDFC)With Cthulhumon as her Leader Digimon on it. Crimson Blood types in the DV6 model number ("666" as shown on the moniter as she types it in)And then she asks for Cthulhumons name, Cthulhumon Malevolently tells her, and she types it in under the Leader Digimon paragraph. Cthulhumon later then corrupts the scoring system and marks Orchid team the winner allowing Crimson Blood to turn the DV6 into a DV7. Background
Cthulhumon warp digivolves from Cthulhumon Larvea Mode and destroys ChaosCyanAgumon to claim the thrown to be the Dark Gaurdian of the Digital World even though he was meant to fight Cyanagumon.