Foretta

Location
is the Mystery Merchant you will find in Popolion Area.
 * Pora Elinu
 * Spirit Outpost, Blessed Woods, east of Fishery
 * Eldritch Academy, Serena's room windowsill, can climb from outside
 * Bloodtalon Camp, next to the princess Rida
 * Popolion
 * Camp Redemption in Cliffs of Insanity
 * Camp Retribution in Cliffs of Insanity
 * Alethea's Last Hope in Vale of the Fang
 * Gloomy Outpost in Paranoon Ravine

Mystery Merchant Shop
's shop information can be found in this list here

Trivia
The only Difference in the all of Arborea's Goblin merchants in the color of their backpack. has a what color Backpack?