Plant Devotion( Complete Champion, p. 61)
Your body takes on the resilience of plants.
Once per day as an immediate action, you can force your body to take on plant characteristics. Your skin becomes brown and barklike, your hair becomes leafy, and your blood oozes like sap. This effect lasts for 1 minute. While in this form, your natural armor bonus increases by 2. In addition, you gain light fortification (25% chance to ignore extra damage from critical hits and sneak attacks). The resistance chance granted by this fortification effect increases to 50% when you attain 10th level and to 75% when you attain 15th level. At 20th level, you gain heavy fortification (immune to critical hits and sneak attack damage) while in this form.
You can select this feat multiple times, gaining one additional daily use each time you take it.|||If you have the ability to turn or rebuke undead, you gain one additional daily use of this feat for each two daily turn or rebuke uses you expend.