Vermin went to the Samurai X Cave to take apart Zane for his metal. Afterward, the Vermillion Army traveled in underground tunnels to their new headquarters. They also attacked the power source to cause a blackout.
They succeeded in retrieving the Time Blade, but Jay came to rescue the Ninja and his mom and the commanders slowed them down. Once freed, the Ninja used the Time Blade to slow the Vermillion down, and the Ninja got away.
Vermin was on the lookout for the Ninja but didn't realize Jay and Cole passed them. Later, they heard a loud sound and went in to check. They were able to outnumber Jay and Cole but when Lloyd and Zane helped, the Vermillion were defeated.
The Vermillion chased the Ninja and regrouped at the dome when they left. Later, when the Ninja were granted access to the Iron Doom, Jay talked and blew their cover. The Vermillion were instructed to attack them, but they were run over by the Samurai VXL. They continued to chase the Ninja to the Iron Doom. When Machia told the Vermillion to go to the Iron Doom, they stopped fighting.
Vermin traveled aboard the Iron Doom back in time to fight the Elemental Alliance. During the fight, Krux and Acronix betray Raggmunk, Blunck, and Machia, destroying them and taking the former pairs control helmets. They then used them to destroy the entire Vermillion Army. The snakes that made the warriors then fused with Iron Doom, including Vermin.
- 'Vermin' means "wild animals that are believed to be harmful to crops, farm animals, or game, or that carry disease." Fitting, as snakes are in several of these categories.
- 66. "The Hatching"
- 68. "Scavengers"
- 69. "A Line in the Sand"
- 70. "The Attack"
- 72. "Pause and Effect"
- 73. "Out of the Fire and Into the Boiling Sea"
- 74. "Lost in Time"