Quote Originally Posted by Rixx View Post
Pathfinder has a quick-and-dirty system for playing monsters where you use the monster's CR as its total "Monster Levels", independent of hit dice, which you can eventually buy off half of. It sounds like it'd suit your purposes:

http://www.d20pfsrd.com/bestiary/rul...onsters-as-pcs
I know, but even with Pathfinder's "improvement" of playing Monster PCs you can still get saddled with unfavorable HD.