Phantom Muspah
From the Pantheon Wiki
Phantom Muspah is an expert boss (combat level 609) found at Ghorrock Dungeon on Pantheon.
Overview
Phantom Muspah can be fought at Ghorrock Dungeon. It has a combat level of 609.
Combat info
See the full Phantom Muspah monster page for stats, attack styles, weaknesses, and the complete drop table.