Zeefzorpul
Zeefzorpul the Imp is an NPC encountered during The Hag's Assistant quest. He has murdered an apprentice of Grizelda the Hag and stolen a recipe of her's.
He is first encountered while searching for the lost apprentice somewhere on the road between Skara Brae and Yew, but specifically on the portion of road between Grizelda's home and the Yew cemetery where the road ends. Typically, he is found before the search reaches past the fork in the road to Minoc. He is seen standing over the charred corpse of the apprentice but then quickly disappears. Opening the unfortunate apprentice's corpse to investigate leads to the next step of the quest.
Later, after roughing up some imps to reveal his whereabouts, a Magic Flute and Map are received to track him down. Typically, the map will lead to a ruin or cave where playing the magic flute will reveal him from hiding. Once he appears, he quickly snatches the magic flute and gives back the recipe he stole before disappearing once more. The next step in the quest is to return to Grizelda with the recovered recipe.
In either brief encounter, he cannot be harmed but also does not attack.