|The subject of this article was removed from World of Warcraft in patch 4.0.3a but is present in World of Warcraft: Classic.
He could hit for 4500-5000 on a lvl 70 cloth wearer and was said to be immune to all damage.
The Cleaner spawned when someone besides the hunter attacked Simone the Seductress during the level 60 hunter quest , and proceeded to kill the interloper and the hunter while Simone despawned. He could also be triggered by attacking Simone in her troll form, however you needed to have over one player or mob on her aggro table, otherwise she would simply kill you with her Fool's Plight.
It seems that a Cleaner spawned whenever damage was dealt by an outsider source, therefore more than one Cleaner could be spawned at the same time.
You dare interfere with this being's testing? The battle must be fought alone! You shall all pay for this interference!