As a Leaper ages, its body begins to disintegrate, and increasingly produces corrosive chemicals as it nears death and becomes a Roller. As a Roller, the creature uses this apparent shortcoming to its advanced by spraying this acidic bile from its mouth, blinding opponents before the creature moves in for a finishing attack using its claws and teeth. This morph is faster than its earlier iterations through the use of trundling locomotion, hence their name. Swarms of Rollers have been known to wipe out sizable troop deployments in a matter of seconds.
Rollers first appear in Bracknell, "In a darker place".
- The lack of long-range attacks leaves a Roller vulnerable at extreme distances. Placing a Backlash Grenade should slow down their advance, if not kill them all completely if used well enough.
- The Rossmore 236 Combat Shotgun, like against Leapers, is also useful against Rollers that evade the player's attacks.
- The Bullseye is also devastating due to its high cyclic rate.
- If the player is going through the game for the second time, the Arc Charger and L11-2 Dragon are effective weapons too.
In Resistance 2 the creatures called Leapers are actually Rollers, having both the acid spit attack and the rolling locomotion of the Resistance 1 enemy. Seemingly the distinction formerly made between the two Leaper subtypes has been discarded, and all adult Crawler forms are now referred to as Leapers.
The creatures called Leapers in Resistance 3 retain the Roller's acid spit attack but due to their bulkier bodies can no longer roll. Producing corrosive acid now seems to be a feature of a healthy Leaper, rather than a product of advanced age as before.