Changeling Metamorphosis (advanced)

Your ability to shapechange is more than skin deep, and you are able to assume more forms than the average Changeling. You gain the following benefits:

• Choose 1 ability score to increase by 1, to a maximum of 20
• When you use your shapeshifting trait, you can grow or hide functional wings and/or a prehensile appendage (tail, trunk, etc)as part of your transformation.

When you use your Shapechanging trait, these benefits last until you change your shape again. 

• If you have wings, you have a flying speed equal to your walking speed. You can’t use this flying speed if you’re wearing medium or heavy armor.
• If you have a prehensile appendage you can grasp things with it. It has a reach of 5 feet. You can use it to do the following simple tasks: lift, drop, hold, push, or pull an object or a creature; open or close a door or a container; grapple someone; or make an unarmed strike. Your DM might allow other simple tasks to be added to that list of options. Your tail/trunk can't wield weapons or shields or do anything that requires manual precision, such as using tools or magic items or performing the somatic components of a spell.

Source: Homebrew, created as a level 2 of Changeling Metamorphosis