Whoa, I just noticed you originally posted this guy half a month ago. I'm surprised I missed it back then- it's one of the crazier monsters I've ever seen.
Maybe, but then again there are dozens of monsters who have instant kill abilities at much lower levels than this and they don't even have to be grappled. Just an attack or a look is enough.
You're right, and this guy allows a Will DC 22 save every round until the character dies. I think my only problem with it is that you need really weird spells to recover the victim. On that note- what happens to any people the Momeh has devoured on the event of its death?
Oh- what are the various save DCs based on? The Mental Blow has a DC 21 Will and the Imbibe Sanity is DC 22.
Sorry to give you a hard time, I just like your monsters being perfect. After all, it's pretty much what we expect from you now, considering how good you are. ;)