In the Plane of Tranquility, Folow the beach south form the zone-in until you get to the giant windmill. Go inside, around back where the gnome is, look up, and click the unmoving cog.
I just saw him spawn at -1106,-1464. Normally A Reef Crustacean is there. There is another Crustacean spawn at -1210, -1387. Maybe both these are PS ...