Hydrasect is a colorful female bee-like monster that mistook a foreign exchange student for Dex. Hydrasect had the ability to fly with the wings on her head and could shapeshift into an even more powerful form known as Arachnida. As Arachnida, she was a large, quadrupedal inhuman spider woman with a set of spider legs on her back and two spider legs for a left arm. Arachnida can shoot strong webbing to entangle Masked Rider. She was killed after Dex snapped one of her hollow legs.