this lil guy spawns in the smallest section of the AiW area. If hes up, and youre running thru he will see invis. Id reccomend using pacify on him if u dont wanna take the time to kill him. Also sometimes all the small critters will chain aggro you since the area is so small that he is in so be careful when pulling. He can be pacified from the start of the AiW area, allowing safe passage by since he sees invis.