|This article is about a/an kaijin in Kamen Rider Black RX.|
Gynakamakil is a black-haired lizard/mantis monster. He can detach the blades on his back to throw them and use them as weapons. He is commanded by Bosgun who accompanied him to attack Kohtaro where Gynakamakil manipulated aluminum cans. The second time, Joe disguised himself as a bride to lure out Gynakamakil. While Kohtaro and Joe were fighting Gynakamakil, Bosgun used his new sword on the car that Reiko was hiding in and made off with her. When Kamen Rider Black RX caught up to where Bosgun and the Chaps had the other brides, he ended up fighting Bosgun and Gynakamakil. Kamen Rider Black RX became Robo Rider so that Bosgun's sword could not penetrate him, resulting in its destruction. He then followed up with an attack on Gynakamakil. Robo Rider reverted to Kamen Rider Black RX and destroyed Gynakamakil with his Revolcane.