I can confirm that on Dec 17 2006 this MOB still exists... spawns in the Bloodpool Room before Inner Sanctum. Spawns on the middle rug in the middle.
Unconfirmed if he spawns elsewhere, my guess is that he used to spawn in all spots along the pool, but has been gimped down to a single spawn location -- which would account for the severe cut-back in his appearances.
I'm trying to confirm something. As of a month or so ago, he used to spawn every 2nd or 3rd placeholder on the Drinal server. Now he seems to be a much rarer spawn. One Saturday morning I went through six full clears (roughly three hours) of the pool area without a single spawn. A few days later when I was there with a friend, he spawned twice in a row. /boggle