Stone Form

(Races of Stone, page 144, DnD 3.5)

[Wild]

You can use wild shape to assume a rocklike form

Prerequisite

CON 13, wild shape ability

Benefit

As a standard action, you can spend one of your uses of wild shape to assume a stony and rocklike form. While in this form, you gain a +4 bonus on Fortitude saves against poison. Your natural armor bonus becomes +4 (replacing any natural armor bonus you normally have, though you retain any enhancement bonus to natural armor). You also gain a slam attack that deals bludgeoning damage equal to a morningstar appropriate to your size (2d6 points for Large characters, 1d8 points for Medium characters, 1d6 points for Small characters).

Normal

Without this feat, a druid can only use wild shape to assume the form of an animal, plant, or elemental.