Akali's Abomination

This spell transforms you into a Yuan-ti Abomination with wings, and can be cast as a reaction. You have a flying speed equal to the Yuan-ti's walking speed.
The transformation lasts for the duration, or until you drop to 0 hit points or die.

You assume the hit points of its new form. When you revert to your normal form, you return to the number of hit points you had before you transformed. If you revert as a result of dropping to 0 hit points, any excess damage carries over to your normal form. As long as the excess damage doesn’t reduce your normal form to 0 hit points, you aren't knocked unconscious.
You are limited in the actions you can perform by the nature of your new form.

Your gear melds into the new form. You can’t activate, use, wield, or otherwise benefit from any of your equipment.

Additionally, by taking this spell you gain access to an innate feature that can be used a number of times equal to your Proficiency Bonus, resetting on a long rest. This feature allows you to turn into a "Poisonous Snake" or a "Flying Snake".