Location: Fangorn, at Treebeard and in the northeastern corner of the forest.
Quest: Ask Treebeard about poison or trees. Treebeard will be sad about something poisoning the trees. At twisted roots you can't go down because roots block the way. The solution is to get a small pouch (stun pouch) from the Master Assassin in Tharbad. Use this pouch at the twisted roots in the north eastern part of the forest. Another way is to remove poison on them like 30 times; the message you get is: “As you finish your incantations, a thick clump of intertwined roots writhes in agony and slowly wither into nothingness.”
Note: As of 11.2007, these roots seem to be able to see through shroud. Suggestion for how to do it now: get a warrior (or really any class), have them remove their weapon, and let them buff while the caster spams remove poison on the roots.
You can go down of them now, and kill a monsterous spider. This spider hits hard and very hard to stab, but it is blindable. Butcher its corpse and bring the chelicera to Treebeard.
You have a limited time to get the chelicera back to Treebeard after triggering his quest. If in doubt, get the chelicera, then go to Treebeard and trigger the quest before giving it to him.
Black Numenoreans get no response from Treebeard when trying to trigger the quest. Can they still get this reward somehow?
Note: Don't kill roots, as they will block the exit when they die. Don't fight spider down of roots, if you flee up you can't reenter. However, this is only if you use stun pouch - using the other method mentioned above will allow to access to leave and go in as much as you want. The spider does not hunt into the room with the roots; it stays underground. The intertwined roots do not see through shroud either - although they will still block you down. If you plan on using remp, and are the only with it there, have at least min mana remp, and be prepared to cast it a lot. They regen against it fairly fast against remp from what I've noticed.
Reward: +1.xx wil for some weeks (depending on playtime), or until your character dies. It seems the reward is more than +1 and less than +2 wil, and may or may not be dependent upon your character's wil before receiving the reward.
For orcs give the Fang to the scout gm in noc to make a dagger with very strong venom like poison attachted to it.