From Guild Wars Wiki
Rockshot Devourers are
rangers who use
traps and interruptions to shutdown the enemy rather than inflict massive damage. They tend to burrow underground, but if they are patroling you can expect to encounter their traps within their patrol area which will inflict blind and burning. They have a high level of elemental armor (e.g. they take 50% damage from fire attacks) and are hence more suseptable to physical damage. They can often be found with
Jade Scarabs.
[edit] Locations
[edit] Missions
[edit] Skills
13 Expertise, 11 Wilderness Survival.
[edit] Items dropped