Doing Hunter Achievement, I followed the spawn points and wasn't having any luck. I decided to pull all of the "Snowfang Spearguards" inclusive of the two mentioned, and kill them all. Also, there are two which spawn on the Iceberg directly east from the camp. Respawn / spawn / pop time seems to vary between 7 minutes and 30 seconds and 15 minutes depending on which PH. The PH which he spawned from came from a 7 min 30 second PH.
Confirming what Lymark mentioned, he appears to spawn from ANY of the "Snowfang Spearguards."