Rift Mob:Sicklefang Spiderling  

Periodically the area south of the road by Scarwood Reach becomes infested with more spiders than usual. This is a very bad thing since the spiderling infestation can spawn in the hundreds.

The secret is that this is part of the Wardstone quest, Bug Hunt, and can only really be done using the Fire Blaster you are given to use for the quest! It is rather unfortunate if you happen to be questing in this area when someone activates that quest!