|This article is about a/an kaijin in Kamen Rider Black.|
Used by Gorgom to capture female college students and use them through surgery involving "Coelacanth DNA Injection" to create female Gorgom warriors for their own desire. Professor Takayama became the Coelacanth Mutant through Gorgom, but took medicine to keep him from changing into it when the transformation is not needed. When Katsumi becomes the next target, Kohtaro was attacked by Katsumi until he brought the Coelacanth Mutant out and escaped during the first battle with Katsumi in its clutches. With the help of some children (whom were really adults turned into kids by de-aging medicine), Kohtaro found the captive female college students just as Professor Takayama became the Coelacanth Mutant which surprised Katsumi. The kids got the captives out (while losing the life of one of them) so Kohtaro can become Kamen Rider Black. Once Kamen Rider Black destroyed the Coelacanth Mutant with the Rider Kick, the explosion destroyed Takayama Research Lab.
Professor Takayama's Coelacanth Mutant form later appeared as one of the Phantom Mutants that are summoned by Fly Mutant through Yuki. It disappeared when Mokoto used his psychic powers to expel Fly Mutant from Yuki.
It can shoot electricity from its fingers, emit laser balls from its hands, and turn into an electrical ball.