Equipped with strange backpack gear, when a Kerchu spotted Ratchet, they would roll up into a ball and charge towards Ratchet. They typically rolled straight and could not maneuver well. If they landed the attack, Ratchet would be knocked back, and the Kerchu would cheer victoriously. Strafe jumping, which, if performed at the right time, would cause them to roll past harmlessly. After rolling, the Kervchu would be dizzy, and vulnerable to a counterattack. They always traveled in packs of two or threes. The Kerchu Guardian disgorged them from its "mouth" during its battle with Ratchet.
Ratchet & Clank Future: Quest for Booty
They were cut from Ratchet & Clank Future: Quest for Booty. 
- These Kerchu foes were set to appear on planet Merdegraw along with the cut Kerchu Carrier, but were removed.
- Kerchu will sometimes roll to their deaths if lured over a cliff.
- Ratchet & Clank Future: Tools of Destruction (first appearance)