Mossy Mandible

A Mossy Mandible is a trophy item.

Acquisition

 * Prophecies
 * Maguuma Jungle
 * Moss Scarabs

Only during Wintersday

 * Prophecies
 * Kryta
 * Nebo Terrace (during The Greatest Snowman Ever Made)
 * Humbugs
 * Nightfall
 * Istan
 * Fahranur, The First City (during Save the Reindeer)
 * Humbugs
 * Issnur Isles (during Find the Stolen Presents)
 * Humbugs
 * Mehtani Keys (during Save the Reindeer)
 * Humbugs

The Wilds
Farm the initial starting area of the Wilds mission, following the circular route that goes up to the centaurs which trigger the bonus, then continue round, and continue part way up the central path that continues the main mission body. It's generally best to stop once you reach the clearing with a boss nearby an Entangling Roots, since the time required to farm Moss Scarabs beyond this point is not worth the reward.

In terms of collecting for Nicholas' gifts, 1-2 runs should collect enough mandibles for a full 5 gift set.