Curefang spawns within the triangle bridge-bridge-GrimlingForest near the wolfcave after the zonerest from the war. I never got him spawned due killing the wandering wolfes.
Some time ago, the sonic hill (where Curfang spawns) was highly populated by pups, wolflings and wolves. This is no longer the case. The sonic hill now has only 2 spawns. Needless to say, having Curfang spawn now can be quite time consuming.
First, whoever owns the sonic cave also owns the sonic hill, so you'll need the wolves in their cave to have this dog spawn.
Curfang still spawns at - or near - the same spot(s) as before. You can get a loc on the Curfang's Heart page.
However, I'm not sure if a certain condition (regarding the war) must be met for him to spawn. I say this because I have camped him for 10 hours today, and have not seen him once. I must say I am very disapointed.
He still spawns, though. That much I can say. Good luck.
He dropped the dagger for me the first time, wanted that heart of his for the added stamina, nice range slotter for a bard. Finally got it one night, soloing him with a lvl 25ish bard. Suprised the heck outta me. He hits hard but apparently not a great amount of hp. He was my first kite. =) Also he is a random pop in the wolf/wolfling series near the creek at the first(?) bridge. Fun fun Warble 39th Jharin apprentice, Proud member of the Coeur de Lion. Morell-Thule
Curfang POPS north of first bridge ( coming from Shar vahl ) about 250 range on wolfie beach . I have killed him once solo ,with my 33 rd rogue ; would have been easier without the 4 adds i got while trying to finish him and loot before i died , trying to get dagger , got no drop ring instead ,AC 4 + 4 str + 4 int + 10 mana > not bad , too bad i can't give to my enchanter .