(Hiccup reading)
Night Fury: Speed: Unknown. Size: Unknown. The unholy offspring of lightning and death itself. Never engage this Dragon. Your only chance, hide and pray it does not find you.
-
Hiccup
You know, I just happened to notice the book had nothing on Night Furies. Is there another book? Or a sequel? Maybe a little Night Fury pamphlet? WHOA!
In the original How To Train Your Dragon, when Hiccup looks up the existing information about the Night Fury dragons, everything is listed as being "unknown", yet everyone seems to be able to immediately identify that Toothless is a Night Fury.
This continues into the second movie, where Eret, Valka and Drago all immediately recognize the species. Valka states that Toothless may be the last surviving Night Fury.
The Night Fury species seems to be awfully recognizable for a species that is supposedly all but extinct, and that no information is known about it.
What happened to the rest of the Night Fury dragons? Is this addressed in any of the extra materials, or in any of the books?