User blog comment:Lord Loss/Monster Hunter Frontier G 2 Discussion/@comment-6050823-20130828112616/@comment-6050823-20130829004912

The G-Rank Unknown was discovered suddenly, pretty much meaning it wasn't known until recently.

It was treated as an unconfirmed monster from lack of sightings until recently, it was called the Black Fox Wyvern from its apparance though its only a temporary name(Hopefully this means it'll get an actual name sooner or later).

Thats all I could find on it though I like to learn more about it.