The Ghost of Nate Raidhawk appeared when Nate was creating potions, unknowingly adding a wrong ingredient. The ghost came out of the potion itself as Nate dropped the bowl on accident. It now roams Tortuga, in the Misty Mire, or Rat's Nest.
This rather mysterious ghost has an orange shade, and has a good atitude and gives good plundering advice. Although, if you get him angry, expect an instant knock out..