Faerie Steed  

They can be found with Faerie Horses, south of the two big mushrooms on the road to Caille and Druim Cain. Look far up the hills, on a plateau, near a camp with Mikka. Be careful of Fee Lions.

I don't know exactly where they spawn but we were leveling at the Prath Farm when a echanter yelled for help an came running at us. Guess what was chasing him. It looked like he came from east of the stables at the farm. Good luck.