Bestiary entry from the Clan Primer:
This creature always drops a trophy when it is defeated. This trophy is used in the Hunt Club side quest which involves trading in the trophies for items, armor and accessories.
|Common - (55%)||Mirror Scale|
|Uncommon - (10%)||(Nothing)|
|Rare - (3%)||(Nothing)|
* The Dreadguard had a 40% chance of spawning when you enter the Walk of Dancing Shadow in the Feywood. Just leave and re-enter the area of it does not appear. Also, it will only appear if you have initiated the Hunt Club side quest.