User blog comment:Dragonmentor123/Is there a reason that Toothless might be the only night Fury?/@comment-24018437-20140827152331/@comment-25273047-20140827171912

Not only that, a comet that somehow wipes out all dragon life on the entire planet but rather conveniently leaves humans and presumably all other animals and organisms unharmed, assuming Hiccup is still present at the end to drop the lovely closing line that everyone just can't wait for.