Cassis Worm Dimidius (カッシスワーム・ディミディウス, Kasshisu Wāmu Dimidiusu^?, 41-42): The first form is Cassis Worm Dimidius. His unique power is "Freeze" or the ability to stop the flow of time to the point in which even the power of Hyper Clock Up is purposeless. He was defeated by Hyper Kabuto's Maximum Hyper Cyclone.

Cassis Worm Gladius (カッシスワーム・グラディウス, Kasshisu Wāmu Guradiusu^?, 42-44): The second form is Cassis Worm Gladius. His power in this stronger form is advanced into "Absorb" or the ability to absorb other Worms and tachyon energy to gain their powers. He can only absorb tachyon energy sequencially. Simultaneous application of tachyon-based attacks will result to neutralization of the absorbed tachyon. He was weakened by Kabuto, Gattack and Kick Hopper's (Triple) Rider Kick and ultimately defeated right after by Hyper Kabuto's Maximum Hyper Cyclone.

Kamen Rider Decade
To be added

Cassis Worm Clipeus (カッシスワーム・クリペウス, Kasshisu Wāmu Kuripeusu^?, 45-46): The third form is Cassis Worm Clipeus. His power in this form is "Clone" or the ability to split himself into two entities. In addition to the blade arm gained in the previous form, he now gets armored plates and shields across his body. The first copy was destroyed by Gatack's Rider Kick, while the second one was destroyed by Kick Hopper's Rider Kick and Punch Hopper's Rider Punch.