Spider Fangs are items that can be gathered from dead Giant Spiders, Sand Spiders, Frost Spiders and Lava Spiders. One can turn in 5 Spider Fangs to Duvalle at the Bank in Lerilin for 25 Volcanic Ash and 10 Experience Points. Duvalle will also accept 50 Spider Fangs in return for 250 Volcanic Ash and 100 Experience Points. Spiders always drop two fangs. A good way to collect Volcanic Ash in Oberin is to collect fangs in multiples of 5, and to do the quest repeatedly.