Mandible is a cactus monster composed of jaw-like pincers who assisted Nefaria and Gork in Count Dregon's plan to capture Ferbus and steal the Masked Rider powers. It can emit a vine from its mouth and launch its jaw-like pincers. Once Dex rescued Ferbus, he engaged Mandible and Gork in battle. When he got caught on Mandible's vine, he called for Combat Chopper and broke free from his vine. While riding on Combat Chopper, Dex destroyed Mandible with his Electro Saber. Fits the category of Gork's monsters.