The Fang of Mohegan is a necklace that has a chance of doubling the number of charms received from drops when worn, with the message You hear a distant wolf howl. appearing in the chatbox when it happens.
It should be noted that the Fang of Mohegan will not activate while under the effects of the triple charm reward from Familiarisation. The fang will double a total of 250 charm drops, after which it loses the doubling effect. This necklace does not double the charm drops from NPC's that drop multiple charms at a time.