Fablegender

Fablegender, or genderfable, is a gender that is strongly connected to mythical beings, and for people who kin with such, like mermaids, unicorns, angels, etc.

History and Flag
The term and flag were coined by Tumblr user mightyistrying.

Etymology
"Fable" means a short narrative, often with mythical elements such as mythological creatures and talking animals.