Mechanical Raban has a round head similar in shape to a turtle's shell. It also has a ovular body with thin arms and human-like hands. The entire mecha's body is decorated with dark stripes, similar to its organic counterpart. However, these stripes run all the way around Mechanical Raban's body and are straight instead of wavy. Mechanical Raban also bears four spots on their forehead.
After the scientist Ichiro Mizuki is injected with the blood of Godzilla by his rival Jiro in an attempt to kill him, he mutates into a giant monster that then attacks Japan. After the Japanese military's failed attempt to destroy the monster with conventional weapons, they turn to Jiro. Jiro's plan is to construct a mechanical version of Raban which he would pilot to fight the real one. However, Jiro's sister Keiko begins to believe Raban may really be Ichiro because the monster is wearing a good-luck charm that she gave Ichiro before he went to Papua New Guinea. With this information, Keiko seeks out Ichiro's mother and discovers that Ichiro and Jiro are actually brothers. Just as Jiro completes the construction of his mechanical Raban, Keiko informs him of her findings leaving Jiro unable to continue with his plan to kill Raban. Now knowing Raban is his mutated brother, Jiro begs the Japanese prime minister for the funds necessary to cure Ichiro, and eventually is able to remove the Godzilla blood from him returning him to normal.
It is unknown what weapons Mechanical Raban possessed, if any, however it is assumed it would have at least had extreme strength to match Raban's.
- Mechanical Raban uses the concept of a mechanical monster being constructed to fight an organic monster, a theme that would not be made popular until Mechani-Kong's appearance in the 1967 film King Kong Escapes and MechaGodzilla's appearance in the 1974 film Godzilla vs. MechaGodzilla, predating both by tens of years.