Wings or tail?

When coming of age, those of her kind could choose between immaculate wings and a phenomenal merman/mermaid tail. Never-ending skies or ever-changing waters, abyss above the ground or mysterious depths growing deeper, forever freedom or eternal beauty.

– Tell us, do you want precious wings or an emerald tail?

I’d rather sit on the shore and forever wonder
How I could’ve had both,
Sad about having neither.