is not visible until you approach the edge of the map. It usually spawns with a group of Juvenile Bladed Termites
and Stalking Nephilas
 Items dropped
Hassin and the group of insects around him don't try to attack you or come towards you if you attack them with a ranged weapon. They will also not attack your pet either if your pet goes and attacks them while you are attacking them with the ranged weapon.
Hassin and the group will not scatter when you use AoE skills, for example Fire Storm
, if you are right on the edge of your range and don't attack them with your weapon.