The tougher cousins of chuds, chobos wield pipes instead of using claws. Chobos do bashing damage, and if they get a good hit in on an arm or leg they will give you a broken limb. Be aware, though, as they do have some skill with their pipes and will attempt to parry your attacks if you have the same or lower parry class as them (1).
You can find chobos scattered all along the sewers. Beware of going too far north, however, as crocs and alligators will attack you.