Some time around 1980 a Barbarian named Aagar climbed into an 150ft long Chambered Nautilus and met his untimely death.
Ever since that day his bane has been one of my favorite Monster's to hate. It's Called the Morkoth or the Morlock. If that wasn't enough he was refered to as the "Wraith of the Deep".
Alas, it's been roundly ignored by mainstream nerdia since then. No D&D miniature and no 4th ed. Monster Manual.
I think that this a glaring oversite, 'cause this guy is nasty!
Basically the Morkoth lures you into his lair, hyponotizes you, then starts munching on your extremities while you are still alive. Not a good way to go. If anyone has ever seen a Pewter of this guy you have to let me know. 'Til then I will be lobbying Wotc for this guys' inclusion in MM3.