Golem Body (3.5e Feat)

Becoming more like an actual construct, you've gained some of their immunities.

Prerequisite: Str 20, Con 24, Fort Save 15+

Benefit: When you take this feat, you gain immunity to critical hits, effects requiring a Fortitude save, death from massive damage, nonlethal damage, stunning, ability damage, ability drain, and death effects or necromancy effects. In addition, you gain bonus hit points based on your size as shown here.

Normal: Unlike other constructs, a living construct are subject to critical hits, effects requiring a Fort save, death from massive damage, nonlethal damage, stunning, ability damage, ability drain, and death effects or necromancy effects.