Based on the commission I got from David Petersen,
http://www.furaffinity.net/view/30871248/

Terith's "Fantasy Outfit" is meant for medieval and similar fantasy settings... including perhaps any ventures into Ironclaw, Pathfinder, or... well... Mouse Guard, obviously. XD
He used to have a tunic thing going on and... I guess he still can but... I really wanted to roll with the look David drew. And hey, its not like I'm one to complain about not wearing pants... <.<;

The only dedicated lore elements to fantasy Terith is that he's an archer. Probably not the best one, but reasonably competent. And I tend to suggest that he's a town guard or something in these settings... unless specifically MouseGuard-related, in which case they're an actual patrolling guardsmouse.