Yep, "Fatality!" makes that a possibility...sorta.
Er...thanks to the feat, an Unarmed critical MIGHT dismember something, but the real likelihood of dismemberment (and the greatest effectiveness of the feat outside of mere limb damage) comes when you start using weapons such as the Power Fist.
In other news, Grugg has (by a noticeble margin) the highest combat-based stat, over 50 even at level 1. However, he is in the unique position of having a score of 0 on certain skills. 0.o
My introduction of the Perfectionist trait almost broke the game.