|This article is about a/an Dopant identity in Kamen Rider W.|
- 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.
- 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
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.