Deformity (Gaunt)( Elder Evils, p. 13)
Through intentional starvation and macabre operations, you are grossly underweight. You have a skeletal appearance, and your weight is now half normal for creatures of your kind.
Willing Deformity (HH) ,
You gain a +2 bonus to Dexterity and a —2 penalty to Constitution. Furthermore, you gain a +2 circumstance bonus on Escape Artist checks and Intimidate checks.