Neo Organism

The Neo Lifeform (ネオ生命体) is the main antagonist of Kamen Rider ZO, a pool of a living fluid that relies on the container it lives in to survive.

Kamen Rider ZO
The Neo Organism was created by Doctor Mochizuki in his attempt to create a "perfect lifeform", taking on the deformed appearance of the doctor's son Hiroshi Mochizuki (望月 宏) but lacked emotions and having a god complex. The Neo Organism then held its creator captive when he refused to complete its evolution to confine the creature within its pool.

The Neo Organism spawns a medium vessel to act through on order to find Hiroshi and use as a means of forcing Mochizuki to completing it, the extension assimilating matter in a junkyard to assume a grotesque form known as Doras. When Masaru Aso interfered, Doras created Doras Monsters to deal with Kamen Rider ZO and capture Hiroshi. After Hiroshi was captured, Doras confronts ZO when he rescues the boy and absorbs the Kamen Rider before proceeding to threaten Hiroshi's life. But the music from Hiroshi's pocket watch revives ZO so he can break free from Doras' body while Mochizuki destroys the Neo Organism's life support. ZO then finishes Doras with his ZO Kick, the monster dissolving while Neo Organism ceases to be.

In an S.I.C. Hero Saga crossover with Kamen Rider J, Doras gains the power of the Fog Mother, gaining different forms as a result, Red Doras Ver. 2, Doras Ultimate Form, and Fog Doras.

Kamen Rider Decade: All Riders vs. Dai-Shocker
Doras, among many other revived monsters, was part of the Dai-Shocker army in the World of Decade that was fought and wiped out by a gathering of 25 Kamen Riders.

Kamen Rider × Kamen Rider W & Decade: Movie War 2010
In the epilogue film of Kamen Rider Decade, Super Doctor Death, seemingly creates another Neo Organism to destroy Kamen Rider Decade. In its deformed child form, it refers to Shinigami and the Bee Woman as "Mama" and "Papa". Still when Bee Woman releases it after being defeated by Electro Magnetic Wave Human Tackle, the Neo Organism absorbs her and spawns a Doras that goes on a destructive rampage with Oberst Zol attacked by it. Doras overpowered Decade and his comrades until the Riders from the Nine Worlds arrived to help and with Decade Complete Form turning them into their Ultimate Forms they destroy Doras. But the Neo Organism controls the Super Crisis Fortress as its fight with Decade collides with that between Double and the Dummy Dopant.

After the Super Crisis Fortress is destroyed, surviving it, the Neo Organism assimilates the Dummy Dopant to assume the form of Ultimate D. Ultimate D was able to overpower the Riders. Fortunately Decade produced the Kamen Rider W Final Form Ride Card to make Kamen Rider Double into CycloneCyclone and JokerJoker and with the Final Attack Ride Card Triple Extreme they destroy Ultimate D.

Ultimate D is described as the most powerful and evil monster of Super Shocker, as it was able to easily overpower many Kamen Riders with little effort. It had the ability to shoot out orbs of energy and greater fighting skills than any of Doras' forms.

OOO, Den-O, All Riders: Let's Go Kamen Riders
Due to a change in history caused by Ankh leaving a O Medal behind in 1971, Shocker achieved its goal of world dominion with the Shocker Greeed which defeated the Double Riders, and new members from the various groups that would had manifested in the normal timeline after Shocker's destruction. Doras was among the many monsters who were part of the this alliance. As more and more of the Kamen Riders started appearing and fighting Shocker's forces, ZO fought against Doras once more.

Kamen Rider × Super Sentai: Super Hero Taisen
Doras was revived as part of Dai-Shocker in the "Super Hero Taisen" incident, led by Tsukasa Kadoya/Kamen Rider Decade, rivaling Captain Marvelous/Gokai Red and Dai-Zangyack. When Joe Gibken became Gokai Blue and charged to attack Decade, Doras tried to stop him. After he was beaten back by Decade, Joe was forced out of his transformation by Doras, who was about to kill him before Captain Marvelous intervened and swiftly destroyed the monster when it let its guard down.

Heisei Rider vs. Showa Rider: Kamen Rider Taisen feat. Super Sentai
Doras was resurrected as part of the revived Badan Empire. When the 15 Heisei Riders and 15 Showa Riders joined forces to defeat Badan, Doras was destroyed along with three Chaps and one Destron Combatman by Kamen Rider Hibiki's Ongeki Da: Kaen Renda no Kata.

The Masked Rider: Kamen Rider ZO
Through his appearance in ZO, the Neo Organism/Doras is featured in The Masked Rider: Kamen Rider ZO.

All Kamen Rider: Rider Generation
Doras appears as a boss in the video game All Kamen Rider: Rider Generation.