The Shocker Kaijin are the "monsters of the week" in the 1971 Tokusatsu series Kamen Rider. They are cybernetic mutant monsters created by the Shocker organization from human test subjects that have been infused with plant or animal DNA to turn them into superpowered soldiers. They are used by Shocker for a variety of operations, including infiltration, assassination and outright terrorism.
After Shocker was recreated Gel-Shocker, the Shocker Kaijin were succeeded by the Gel-Shocker Kaijin.
Shocker's kaijin are created from human test subjects who underwent the remodeling procedure done by Shocker's scientists. While some willingly allowed themselves to be experimented on, including the Shocker executives themselves, most test subjects were kidnapped by Shocker and forcefully transformed into kaijins, losing their free will in the process and becoming loyal servants of the Shocker organization.
All kaijins possess enhanced strength and durability thanks to a combination of cybernetics and genetic engineering. They are each infused with DNA from either plants or animals, granting them unique abilities depending on the life form whose DNA they borrowed. Beyond their individual specialized abilities, kaijins all share the ability to imitate the forms of humans in order to blend into society and infiltrate places.
Kaijins primarily serve as low-level commanders or agents of the Shocker organization, and are the main operatives used by Shocker in their terrorist attacks. Most kaijins command their own squads of Shocker Combatmen though some are high-ranked enough where they are placed in charge of entire Shocker branches, like Saboteguron who commanded the Shocker Mexico branch. All three of the top Shocker executives (Colonel Zol, Dr. Shinigami and Ambassador Hell) have also underwent the remodeling procedure to enable them to assume Kaijin forms.
The first Shocker Kaijin seen was Spider Man, who was sent to abduct Takeshi Hongo so Shocker could convert him into the cyborg supersoldier Kamen Rider. However, after the remodeling procedure was done on Hongo, one of the scientists working on the project, Professor Midorikawa, defected from Shocker and helped Hongo to escape, beginning the first Kamen Rider's crusade against the Shocker organization.
The kaijin of Shocker's Japan branch initially operated independently, but starting with episode 26 the Great Leader would place one of his lieutenants in charge of overseeing the operations of the Japan branch and directing the kaijin.
After Shocker restructured itself and merged with Geldam, the Shocker Kaijin would be succeeded by the Gel-Shocker Kaijin. Unlike the Shocker Kaijin before them, Gel-Shocker Kaijin are infused with DNA from two plants or animals instead of one, often granting them each a combination of two unique abilities derived from the lifeforms they borrowed DNA from.
Kamen Rider V3
As part of Doktor G's scheme to drop poison gas on several key regions of Japan, a number of Shocker kaijin were resurrected to aid the Destron Inhumanoid Quoit Kuwagata in carrying out the attacks. They all fought against V3 when he attacked Destron's base but were no match for his power.
OOO, Den-O, All Riders: Let's Go Kamen Riders
After coming across a Core Medal Ankh had dropped while time-traveling to the year 1973, Shocker was able to use it to produce their strongest kaijin, Shocker Greeed, creating an alternate timeline where Gel-Shocker succeeded in defeating the Double Riders with Shocker Greeed and conquering the world. By the year 2011, numerous Shocker kaijin acted as enforcers for Shocker's one world order, along with the kaijins of other evil organizations that had been annexed into Shocker.
Kamen Sentai Gorider
In the three-part web series, numerous Shocker Kaijin were among the horde of revived monsters in the Game World created by Kuroto Dan as part of a contingency plan he set in place to revive himself. The horde of kaijin battled against Emu Hojo and the other four revived Riders summoned to the Game World, but no matter how many times they were defeated, they would endlessly revive and attack again.
After his scheme was exposed by the real Kazuma Kenzaki, Kuroto Dan led the kaijin horde in a final attack on the real world, only to be defeated by Emu Hojo and the second Gorider team comprised of Kaito Kumon, Kazuma Kenzaki, Kiriya Kujo, Yoko Minato and Kaoru Kino.
- Spider Man
- Bat Man
- Scorpion Man
- Mantis Man
- Grimreaper Chameleon
- Bee Woman
- Cobra Man
- Shocker Greeed
Colonel Zol's Kaijin
- Antlion Thunder
- Experimental Wolf Man
- Golden Wolf Man
Dr. Shinigami's Kaijin
- Fly Man
Ambassador Hell's Kaijin
- Sea Snake Man
- Cockroach Man
- Poison Lizard Man
- Earthworm Man
- Owl Man
- Takeshi Hongo/Kamen Rider 1 (defected)
- Hayato Ichimonji/Kamen Rider 2 (defected)
- Shocker Riders
- Shocker Rider No. 1
- Shocker Rider No. 2
- Shocker Rider No. 3
- Shocker Rider No. 4
- Shocker Rider No. 5
- Shocker Rider No. 6