Swabs were electrified hunchbacked space pirates that hid in chests, then jumped out when a foe was near and attacked. They often accidentally destroyed any other space pirates nearby. They were heavily armored, and combined with their electrification, they were deadly enemies.The Fusion Bomb, when equipped with Concussion Detonators, could hold them at bay while in use with another weapon. They were later replaced by Elite Swabs, which were Red and Grey colored Swabs who were stronger than normal Swabs. They also had stronger attacks and were harder to beat.
Captain Slag was likely a Swab as he was electrified and also used a Hook as a weapon. If Ratchet is touched by a Swab, he would likely die immediately. When the Tornado Launcher is used on the Swabs, they can still electrify the player while in the tornado.