|This article is about a/an ally in Kamen Rider Kiva.|
In 1986, Riki lived in human society as a masseur in Ramon's parlor before moving into the Café mald'amour to work there for a bit, falling in love with Yuri after eating her food. When Jiro left, Riki joined Ramon to become a kakigoori seller until Jiro asked for their aid at defeating the Rook. All three Arm Monsters, Otoya and Yuri eventually managed to defeat him. After some time passes, Ramon and the rest of the Arm Monsters would soon face the Fangire King whom they managed to get away once, then unsuccessfully trying to kidnap Maya to act as a shield from him. As they were faced by the Fangire King once more only to lose again, they were given a choice between dying or killing Otoya themselves. After finding themselves unwilling to kill Otoya to save themselves (as per the King's offer), Riki decides to flee. After seeing Ramon sealed by the King, Riki attempts to run away, but is sealed into the Demon Iron Hammer Dogga Hammer (魔鉄槌ドッガハンマー Matettsui Dogga Hanmā). They were eventually freed by Otoya during the midst of the battle against the Fangire King. All three soon run away during the confusion. After the Fangire King was defeated, the Arm Monsters decided to go inside Castle Doran, though not before promising Otoya to help his unborn son in his place. This leads to Riki now aiding Wataru in 2008, his Dogga Hammer used by Kiva to assume Dogga Form (ドッガフォーム Dogga Fōmu).
Ramon appears with his fellow Arms Monsters in Cho Kamen Rider Den-O & Decade NEO Generations: The Onigashima Battleship.
A rather slow and dim guy, Riki initially acted like an average Fangire, secretly feeding off human life energy while getting mad at any human that doesn`t act the way he wants them to. After meeting Otoya, Riki somewhat changed for the better as he seemingly stopped killing humans. He even went as far as to not kill Otoya when the Fangire King made Riki choose between dying or killing Otoya himself. In 2008, Riki became more obedient and pessimistic while helping Wataru.
- Height: 270 cm
- Weight: 320 kg
Riki has superior strength compared to the other Arm Monsters and feeds by grabbing a person and draining the soul out in the form of electrical discharges. He acts as Castle Doran's butler, assuming his true form by pounding his fists together. He can only speak in a slow, monotone voice, and is thus not as talkative as Jiro or Ramon, usually having one of them speak for him. In addition to his habit of popping his neck, Riki can eat things that are inedible to normal people. In his Dogga Form, Riki is durable enough to withstand being attacked by members of the Checkmate Four despite being weaker than them. He also defeated multiple revived Fangires in 2008 hinting that Riki became stronger as time passed. He along with the other Arm Monsters can also lend their powers to Kiva and presumably future Kiva through Fuestles. This is to the point where they can combine their powers at once to assume DoGaBaKi Form and DoGaBaKi Emperor Form.
Appearances: Kiva Episode
- "Dogga Hammer!"
- ―Kivat's transformation announcement[src]
- "Dogga Bite!"
- ―Kivat's finisher announcement[src]
The Dogga Hammer's finishing attack is the Dogga Thunder Slap (ドッガ・サンダースラップ Dogga Sandā Surappu), before which Kivat must perform a Dogga Bite (ドッガバイト Dogga Baito) on the shaft of the hammer. The ball of the hammer opens up like a hand to reveal the True Eye (トゥルーアイ Turū Ai) in the palm, which can pinpoint a Fangire's exact location or release a shockwave that weakens the opponent Fangire's glass skin, rendering it immobile. Then the head of the hammer produces a giant energy duplicate of itself called the Phantom Hand (ファントムハンド Fantomu Hando), which follows Kiva's swings and crushes the enemy with massive collateral damage. 
Due to the Dogga Fake Fuestle tracing Dogga's frequency, the Dogga Hammer can be used by Ixa. Although it does not cause Ixa to change into a new form as Kiva does, it retains its power and effect regardless. However, Ixa has only been shown using the Garulu Saber, the Dogga Hammer and Basshaa Magnum were not shown being used by Ixa in the series' run.
The Dogga Hammer consists of the following parts:
- Thunder Fingers (サンダーフィンガー Sandā Fingā) - The Dogga Hammer's fingers/main head unit. It is capable of destroying a 10m thick iron plate in one smash. Due to it being made of super-dense Lucifer Metal (いルシファーメタル Rushifā Metaru), the Thunder Fingers can open up to use its palm as a sort of solid shield. The Thunder Fingers can also call lightning from heaven, storing it in the Iron Base to use later on in combat.
- Catena (カテナ Katena, lit. 'chain' in Italian) - A sacred chain that wraps around the Thunder Fingers. The Catena suppresses the Dogga Hammer's power until needed, preventing the Dogga Hammer from running amok from energy overflow.
- Catena Winch (カテナウインチ Katena Uinchi) - The grey metal decorations on top of the Dogga Hammer behind the Thunder Fingers. It senses the Dogga Hammer's current power flow and tightens or loosens the Catena accordingly. The Catena and Catena Winch are necessary to keep Dogga Hammer's power in check due to the Dogga Hammer being the most powerful out of the three Arm Monsters.
- Iron Base (アイアンベース Aian Bēsu) - The Dogga Hammer's wrist. It stores electric energy harnessed from thunder inside its internal Thunder Coil (サンダーコイル Sandā Koiru). A shock absorber is installed on the wrist and can reduce energy kickback of impacts, preventing Kiva from suffering recoil.
- Franken Stamp (Thunderbolt) (フランケンの刻印（サンダーボルト） Furanken no Kokuin (Sandāboruto), lit. 'Seal of Franken (Thunderbolt)) - The Dogga Hammer's hinge that the Thunder Grip folds onto. On the hinge are engraved emblems of a Franken being struck by a thunderstorm. The Franken Stamp was engraved by Dogga to remember the pride of his race.
- Thunder Grip (サンダーグリップ Sandā Gurippu) - The Dogga Hammer's black grip. It is a type of blood vessel, filled with purple blood unique to Dogga. When transforming into Kiva Dogga Form, the Dogga Hammer's power flows to Kiva via the blood vessel, allowing transformation.
- Dogga Fuestle (ドッガフエッスル Dogga Fuessuru): Kiva uses this Fuestle to summon Dogga from Castle Doran. This Fuestle is inherited by Kamen Rider Kiva in 2031.
- Dogga Fake Fuestle (ドッガフェイクフエッスル Dogga Feiku Fuessuru): A Fuestle that copies the frequency of Kiva's Dogga Fuestle, allowing Ixa to hijack the Dogga Hammer when summoned. This Fuestle was not used in the series' run.
- Dogga-Seal Fuestle (ドッガシールフエッスル Dogga Shīru Fuessuru): This Fuestle seals Dogga by emitting a continuous sound, creating an energy sphere that captures Dogga and converts him into the Dogga Hammer.
Legend Rider Devices
The power Dogga lends Kiva is harnessed in the Kiva Dogga (キバドッガ Kiba Dogga) Form Ride Card (フォームライドカード Fōmu Raido Kādo), which is used by Decade to transform into Kamen Rider Kiva Dogga Form. Used once in the World of Ryuki to fight Kamen Rider Knight.
Behind the scenes
The word "dogga" (ドッガ) is a Japanese onomatopoeic sound representation of a great thud; in the case, a hammer hitting, while "Riki"'s name is spelled with the same kanji for "power" (力 chikara).
Dogga was designed by Yasushi Nirasawa (韮沢 靖 Nirasawa Yasushi).
- Riki appears with his friends in Cho Kamen Rider Den-O & Decade Neo Generations: The Onigashima Warship for some short period. He was possessed by Kintaros.
- Riki was the one who revealed to Otoya of Maya`s true nature by confronting her.
- When the True Eye reveal in the palm of the Dogga Hammer, it is very resemble to the Dark General Gaburin (闇将軍ガブリン Yami Shōgun Gaburin), a giant mecha demon hand-like monster also having an eye in his palm from Uchuu Tetsujin Kyodain. Some fans thought that it is also part of special gifts to in memory of Shotaro Ishinomori's 70th birthday.
- "TV Asahi's page for the Dogga Hammer". http://www.tv-asahi.co.jp/kiva/rider/doggahammer.html. Retrieved 2009-06-27.