Not to sound rude, but you could have looked to your left in the tool bar.. found the link for Bestiary, and found this yourself. But scince Im being nice to you Yanks today....
Lieutenant Nianne in Fortress Snowdonia (upstairs at Loc=28707,56500) will request Faerie Frog Eyes. Go to in Snowdonia or Salisbury Plain to kill Faerie Frogs for the eyes. Frogs are located just inside Snowdonia in the lake at the bottom of the first cliff inside the fort, and near the circle of stones. Repeatable 15 times for 1, 040,310 xp per, or sell for 18s 83c each.