The first proposed faegender flag
Faegender is a gender that changes with the seasons, equinoxes, and moon phases; not to be confused with genderfae. The name is likely in reference to the fae/faeries.
History
The second proposed faegender flag
The coiner of this term is unknown, however, it has at least existed before July 30th of 2016, when all 3 flags were coined by pride-color-schemes on tumblr, treating faegender as an already-established term[1].
Resources
The third proposed faegender flag