Cerullean swarmers were small yet aggressive creatures. Using only their razor-sharp teeth to attack, these enemies charged in for the kill. Although they were easily dispatched with most weapons, Ratchet needed to beware of these nasty critters when they appeared in groups.
Cerullean swarmers first appeared on planet Cobalia and were the first enemies that Ratchet encountered in the Polaris Galaxy. Along with its counterpart, the Cerullean centipede, it was named after the Cerullean Sector. However, they were also seen in the Praxus Sector. They seemed to be fond of gelatonium as they were seen usually in gelatonium plants throughout the Polaris Galaxy.
If Ratchet got surrounded, a useful defensive option was the hyper-strike to knock them back and clear them away.