Equipped with a strange backpack gear, when a Kerchu spotted Ratchet, they would role up into a ball and charge towards Ratchet. They typically rolled straight and couldn't really maneuverer too much. If they landed the attack, Ratchet would be knocked back a bit, and the Kerchu would cheer victoriously. Strafe jumping them was best advised, which, if performed at the right time, would cause them to roll right past you. After the Kerchu is finished rolling, it will temporarily be dazed, being vulnerable to a counterattack. Kerchu always travel in packs of two or threes.
The Kerchu Guardian will often spit out these enemies from its "mouth" during the second phase in the boss fight.
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 you lure them over a cliff.
- Ratchet & Clank Future: Tools of Destruction (first appearance)