I designed the dessicated lions for that encounter. IIR, I used the template as described from the deluxe book of templates. Unfortunately, my copy is packed in a box somewhere, as I'm in the middle of a game room transition.
Does anyone have access to the book or pdf that they can confirm the d6 Con damage for each attack, and possibly check if there is a Fort save?
If a don't see a reply in a few days, send me an IM, and I'll spend some time digging out my copy.
My other tought would be to limit the d6 Con damage to just once per round, regardless of the total number of hits. This is similar to a vampire's energy drain attack (see MM). which is a bummer when you desgin a vampire monk