Antlion Thunder - An antlion monster. His emblem, worn by the soldiers under his command, was a silhouette of a head with large horns similar to his own. Has enough strength to knock down Kamen Rider #2 with a good punch and could dig large pits. His soldiers were able to dig through the ground to make surprise attacks. Initially, operated independently, using his pit to attack helpless victims, but ended up working for Colonel Zol after his arrival, in spite of not liking the idea, in an operation to kill Rider #2. Although in their first encounter Antlion Thunder left victorious, with Rider #2 barely escaping thanks to his bike Cyclone 2, he was destroyed in their second battle, when Rider #2 hit him with a Rider Kick, throwing Antlion Thunder into his own pit, where he was quickly buried by the soft sand.
Antlion Thunder returned in the Kamen Rider vs. Shocker movie, where he faced Kamen Rider #1 and Kamen Rider #2, giving time to let Doctor Shinigami escape from them. He was destroyed by Kamen Rider #1's throw.