Bonetooth is the first boss of the 6-man instance Skûmfil, quest mode, left path.
This is considered an easy fight. There are some Blind Fell Corpse-claw adds that can be taken out while the tank fights the boss, to prevent them going for the healer. In worst cases, Bonetooth can even be dazed.
-  Kergrim-leaders Fellowship
Bonetooth is a kergrim named for a terrifying mouth and an adornment of long bones around his neck.