Voice Actor: Midorikawa Hikaru 緑川光
Suit Actor: Okamoto Jirou 岡元次郎
Negataros is the main villain in the crossover movie "Kamen Rider Den-O & Kiva The Movie: Climax Deka".
Negataros is described by Owner as a stray Imagin. His goal is to create the ultimate evil organization, the Negatoros Corps, to take over the world. To do that, he snuck onto DenLiner and stole a spare Den-O Rider Pass while Owner was training, and recruited Imagins, Fangire and human criminals as his mobsters. To show the evil might of his organization, he even blow up his whole base just to destroy the heros. He has a habit of touching his horns when talking. Negataros is eventually stopped by the combine power of Kamen Rider Den-O, Kamen Rider Zeronos and Kamen Rider Kiva.
The design of Negataros is basically a recolored, black version of Momotaros.
Kamen Rider Nega Den-O
Because Negataros possess a Den-O Rider Pass, he can also use the Den-O Belt. Swiping the pass in front of the belt triggers the Nega Form to activate. As with Den-O, Nega Den-O has the Nega DenGasher attached to his belt.
- Armor: Look exactly like Kamen Rider Den-O Sword Form, except it is purple in color with light blue tribal markings
- Weapon: Nega Form can use all four forms (sword, rod, axe, gun) of the Nega DenGasher. As with his armor, the blade of the sword is in purple with tribal markings.
- Finisher Charge: Full Charge
- Gun Finisher: After charging up the gun, it can shoot a powerful dark red energy blast compared to Den-O Gun Form's purple energy blast
Nega DenLiner is a recolored version of DenLiner Gouka with tribal markings all over it. The train's weaponry are replaced by the three versions of giant out-of-control Imagin monsters that will attack in their respective weapons. Nega DenLiner proves stronger in the train battle until Castle Doran arrives. Nega DenLiner is destroyed along with its pilot Negataros by DenLiner, ZeroLiner and Castle Doran's combine power.
- Nega (ネガ) means "negative" in Japanese.
- It was never revealed whether Nagataros has a contract holder.
- Midorikawa Hikaru voiced other tokusatsu series characters, including Salamandes of Kyuukyuu Sentai GoGo V , Aberu of Mirai Sentai TimeRanger (ep 34), TopGaler of Bakuryuu Sentai Abaranger, Incubus of Mahou Sentai MagiRanger (ep 23-24) and Mesuguro Hyoumonchou of Hikounin Sentai AkibaRanger (ep 3,5).