Wild Shape (Su)
Source: Advanced Player's Guide, p. 99
A desert druid gains this ability at 6th level, except that her effective druid level for the ability is equal to her druid level – 2. A desert druid cannot use wild shape to adopt a plant form. At 10th level she can assume the form of a Small or Medium vermin, at 12th level a Tiny or Large vermin, and at 14th level a Diminutive or Huge vermin. This effect functions as beast shape IV (treating the vermin as an animal to determine its ability and natural armor modifiers).