Change Shape (Su): A creature with this special quality has the ability to assume the appearance of a specific creature or type of creature (usually a humanoid), but retains most of its own physical qualities. A creature cannot change shape to a form more than one size category smaller or larger than its original form. Changing shape results in the following changes to the creature:

• The creature retains the type and subtype of its original form. It gains the size of its new form.
• The creature loses the natural weapons, movement modes, and extraordinary special attacks of its original form.
• The creature gains the natural weapons, movement modes, and extraordinary special attacks of its new form.
• The creature retains all other special attacks and qualities of its original form, except for breath weapons and gaze attacks.
• The creature retains the ability scores of its original form.
• The creature retains its hit points and saves.
• The creature retains any spellcasting ability it had in its original form, although it must be able to speak intelligibly to cast spells with verbal components and it must have humanlike hands to cast spells with somatic components.
• The creature is effectively camouflaged as a creature of its new form, and gains a +10 bonus on Disguise checks if it uses this ability to create a disguise.