To save you from reading old posts dating back to 2000 with mixed info as to his spawn info, here it is:
Spawns at 2507, 921, -194 (deep underwater by the base of the aviak ramp that also has the flame of innoruuk; on the island east of the Arena ZL).
PH are Webclaw Murkwave, aqua goblins and aqua goblin shamans.
One of the three (or 4 if it's fabled time) of these mobs will spawn every 4-5 minutes.