True Racial Shapechange

The changeling has mastered the ability to fully embrace the mindset, perspective, and capabilities of a shape and can replicate racial bonuses and powers when taking a form, and gains any racial, non-ability features when in that shape. For example:

• Dragonborn Breath weapon
• Tiefling Thaumaturgy and Hellish Rebuke
• Elvish Dark Vision and Trance. 

This ability does not confer racial bonuses that required time to learn, like AARAKOCRA flight, Goliath Mountain Born, or Dwarven Stone Cunning would not be something you could gain without significant practice / exposure.