|This article is about a/an set of alternate forms in Kamen Rider Gaim.|
- "OOO Arms: Tatoba, Ta~To~Ba!"
- ―Transformation announcement[src]
OOO Arms (オーズアームズ Ōzu Āmuzu) is a Legend Rider Arms based on Kamen Rider OOO's Tatoba Combo. Accessed through the OOO Lockseed or the Heisei Rider Lockseed channeling the OOO Lockseed, this form's Arms Weapon is the Medajaribur.
Sengoku Battle Royaleworld of the Warring Period through the combination of a Helheim's Fruit provided by the Priestess of Fate and the Taka Core Medal left behind by Kamen Rider Bujin OOO. Among a gathering of Legend Rider Arms, OOO Arms was assumed by Armored Rider Baron who used it to fight against Bujin Gaim's monsters before regrouping with Ryugen W Arms, Zangetsu Fourze Arms, and Kamen Rider Beast Hyper to destroy the Utsubokazura Kaijin.
Kamen Rider Taisen
The OOO Lockseed was created from Kamen Rider OOO himself when he was defeated by Riderman's Rope Arm in the final battle of the Rider War between the Heisei Riders and Showa Riders. Ryo Murasame, had planned for this, however. Under the guise of Badan's Ambassador Darkness, Ryo collected the Rider Lockseeds before revealing himself as Kamen Rider ZX, using his Micro Chain to free the Lockseeds which were drawn to Kamen Rider Gaim, using his power to bring back the Kamen Riders, who had been waiting in the Helheim Forest, through the cracks back to Earth so they could all defeat Badan together.
- Kamen Rider Baron (Kamen Rider × Kamen Rider Gaim & Wizard: The Fateful Sengoku Movie Battle)
- Kamen Rider Gaim (Kamen Rider Battle: Ganbarizing)
- Kamen Rider Gaim
- Jimber Ride Wear
- Kachidoki Ride Wear
- Kiwami Ride Wear
- Ride Wear (Drive Arms ver.)
- Kamen Rider Ryugen
- Kamen Rider Zangetsu
- Ride Wear (Watermelon Arms ver.)
- Kamen Rider Gridon
- Kamen Rider Kurokage
- Kamen Rider Bravo
- Kamen Rider Knuckle
- Kamen Rider Bujin Gaim
- Kamen Rider Mars
- Kamen Rider Kamuro
- Kamen Rider Zangetsu Shin
- Kamen Rider Duke
- Ride Wear (Dragon Energy Arms. ver)
- Kamen Rider Sigurd
- Kamen Rider Marika
This form's Arms Weapon is the Medajaribur.
- Kamen Rider Battle: Ganbarizing
- Kamen Rider Gaim