Icon-w.png This article is about a/an Dopant identity in Kamen Rider W.

Beast Dopant (ビースト・ドーパント Bīsuto Dōpanto) is the Dopant form assumed when one uses the Beast Gaia Memory. [1]


Beast Dopant

  • Height: 235cm
  • Weight: 210kg

By gaining the Beast Memory, the user can transform into the Beast Dopant (ビースト・ドーパント Bīsuto Dōpanto) with superhuman strength and self-regenerative powers.

Maruo Arima

Maruo Arima

Main article: Maruo Arima

The main user of the Beast Memory was Maruo Arima (有馬 丸男 Arima Maruo), Suzuko Arima's husband and a bank robber who a decade ago, attempted an armored car robbery at the Futo Dam with his wife. The case was investigated by Soukichi Narumi until the evidence went dry and when Isamu Bito turned himself in for the crime. By the present, now rich, Maruo is still looking for a bear statue that holds the Zone Memory. However, he meets resistance from Kamen Riders Double and Accel, but he defeats them easily. Once the Zone Memory returns to Suzuko's possession, the two return to the Futo Dam to finish their heist, after quickly besting the Riders. There, they face Accel once again, but just when it seems Maruo and Suzuko are going to win, Double arrives. Double pushes himself to his limit fighting Maruo, and beyond, achieving Double's perfect synchronization form; CycloneJoker Xtreme. The Beast Dopant is weakened by Kamen Rider Double CycloneJoker Xtreme's Prism Break Maximum Drive before being eventually defeated by the Bicker Charge Break Maximum Drive.

OOO, Den-O, All Riders: Let's Go Kamen Riders

Beast Dopant was revived as a member of Shocker. He appears when the Shocker army is gathered up to execute Eiji, Kotaro, and Ankh (possessed by Momotaros). He is seen fighting Kamen Rider 2 and V3.

Super Hero Taisen Z

He was revived as a member of Space Shocker. He was seen spotting Geki as he was attempting to leave the Gemnu Castle. After taking on some of the Space Shocker Combatmen, he knocks him down. Beast Dopant walks towards him and is kicked away by a Space Shocker Combatman, who was revealed to Gai Ikari in disguise.

Kamen Rider Drive Saga: Kamen Rider Chaser

Roidmude 077 as the Beast Dopant.

During the events of Kamen Rider Drive Saga: Kamen Rider Chaser, Roidmude 077 has the Beast Gaia Memory which transforms it Beast Dopant. 077, as the Beast Dopant, battles Kamen Riders Drive and Mach until Ryu Terui shows up as Kamen Rider Accel to battle 077. 077 is destroyed by the combined finishers of Drive and Accel and thus the Beast Memory is also destroyed.

Futo Detective


Behind the Scenes

Concept Art

Beast Dopant concept art

Beast Dopant was designed by Katsuya Terada (寺田 克也 Terada Katsuya).


Narumi Detective Agency
Shotaro Hidari - Philip - Akiko Narumi - Sokichi Narumi† - Tokime
Memory Drivers
Double Driver - Accel Driver - Lost Driver
Gaia Memory-related
Gaia Memories - Memory Gadgets - Fang Memory - Xtreme Memory - Trial Memory - Gaia Memory Enhancing Adapter
Metal Shaft - Trigger Magnum - Engine Blade - Skull Magnum - Prism Bicker - Eternal Edge - Shroud Magnum
RevolGarry - HardBoilder - Gunner A - Diablossa - SkullBoilder - SkullGarry - HardMammother
The Fuuto Irregulars
Santa-chan - Watcherman- Queen & Elizabeth - Isamu Bito
Futo Police Department
Ryu Terui - Mikio Jinno - Shun Makura
Museum and the Dopants
Foundation X
The Sonozaki Family: Terror - Claydoll - Taboo/R Nasca - Nasca - Smilodon - Masquerade Dopants
Dopants: Magma Dopant - T-Rex Dopant - Money Dopant - Anomalocaris Dopant - Cockroach Dopant - Sweets Dopant - Virus Dopant - Violence Dopant - Arms Dopant - Bird Dopant - Ice Age Dopant - Triceratops Dopant - Liar Dopant - Puppeteer Dopant - Invisible Dopant - Nightmare Dopant - Beast Dopant - Zone Dopant - Yesterday Dopant - Quetzalcoatlus Dopant - Gene Dopant - Jewel Dopant - Old Dopant - Utopia Dopant - Energy Dopant
Movie Exclusive Villains: Dummy Dopant - Heat Dopant - Trigger Dopant - Metal Dopant - Luna Dopant - Cyclone Dopant - Bat Dopant - Spider Dopant - Kamen Rider Eternal - Commander Dopant - Eyes Dopant
Novel-Exclusive Villains (The One Who Continues After Z): Zoo Dopant - Zero Dopant - Queen Bee Dopant - Flower Dopant - Elephant Dopant - Dolphin Dopant - Salamander Dopant - Fish Dopant - Bird Dopant - Ape Dopant - Bee Dopants
Manga Exclusive Villains (Futo Detective): Road Dopant - Aurora Dopant - Meganeura Dopant -Brachiosaurus Dopant - Scream Dopant - Alcohol Dopant - Puzzle Dopant - Reactor Dopant - Antlion Dopant - Owl Dopant - Trash Dopant - Caracal Dopant - Toadstool Dopant
Yukiji Bando - Kazuha - Hideo - Mamoru Nikaido - Sabu
Katsumi Daido - Maria S. Cranberry - Reika Hanehara - Kyosui Izumi - Gozo Domoto - Ken Ashihara
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