hmm..there's the Darcassian..don't know the site off the top of me head, but there's plenty of links for his stuff at 3d commune, and Rendervisions, I b'lieve..not sure about the monster potential, but the number of arms is right..;)
There was (a long time ago) a 4-armed (maybe even more) add-on for Posette, used to be in Freebies, but it's been years. Hope this is a good start..stay tuned for more coherent and helpful answers..

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)