Changeling Disguise is a racial power gained by Changelings.[EPG:29]
Changeling Disguise
Changeling Racial Power
You alter your form to look like another person.
At-Will ✦ polymorph
Effect: You alter your physical form to take on the appearance of any Medium humanoid. You retain your statistics in your new form, and your clothing, armor, and possessions do not change. The new form lasts until you change form again.
Any creature that attempts to see through your ruse makes an Insight check opposed by your Bluff check, and you gain a +5 bonus to your check.