Fatugender is a gender that doesn't matter, or feels useless in nature. Fatugender can also be a xenogender, where one's gender can only be described through the feeling of uselessness, or it can be a term for any gender that simply just feels useless or unnecessary. People who are fatugender may also identify as fatugirl, fatuboy, fatuenby, etc, or they may just be fatugender.
Flag
The flag was coined by tumblr user autistic-italy, and while the colour meanings are unknown, it's commonly known the emoji in the middle represents shrugging. This emoji is nicknamed Shruggie and is put on the flag to represent shrugging, or not knowing the answer to something, hence being "useless."