@SageAdviceDnD @JeremyECrawford So , If a Changeling uses it's "Change Appearance" feature to transform into a humanoid with flying, climbing or swimming speeds, would the changeling be able to use those speeds? Would a Changeling transformed into an Aarakocra be able to fly?

— Júlio (@halfwhitebigode) January 3, 2019

@UncleCoryDM hit it on the nose. You gain the appearance, but nothing else. If your ruse depends on those traits you are emulating, make sure you have a spell, feature, or item that allows you to perform said task. Spell for flight, potion for the water breathing of aquatic races

— Michael Greszler (@TheLink484) January 3, 2019

Correct. If you're a changeling and you assume the appearance of a tortle, you don't get a bonus to AC. Having what look like wings doesn't mean you have the bone structure or musculature required to use them effectively. The default changeling ability is a DISGUISE.

— Keith Baker (@HellcowKeith) January 3, 2019