Cryptidgirl is a term which describes one's gender as "outwardly identifying as a woman, and inwardly as a cryptidlike entity", such as mothman, yeti, jersey devil, etc.
The masculine equivalent is Cryptidboy.
History
Cryptidgirl was coined by Tumblr user heartfelt-angel on June 10, 2021.[1]
Flag
The flag was created by the same user on the same date. It has no confirmed meaning.