Mothra Aasimar (5e Subrace)
From D&D Wiki
Aasimar of Mothra decent are the descendants of the great Mothra, who is a moth goddess that protects the world and the many races who inhabit it from harm.
They are imbued with fey and celestial magic alike, spreading scales from their wings when their divine energy erupts from their body.
Ability Score Increase. Your Dexterity score increases by 1.
Fey Ancestry. You have advantage on saving throws against being charmed and magic cannot put you to sleep.
Wrath of Mothra. Starting at the 3rd level, you can use your action to unleash the divine energy within yourself sprouting a pair of moth wings from your back. Your transformation lasts for 1 minute or until you end it as a bonus action. During it, you have a flying speed of 30 feet. In addition, at the end of each of your turns creatures within 20 feet of you take acid damage equal to your level. Once you use this trait you must finish a long rest until you can use it again.