Curate, connect, and discover
i still believe that Night Furies are still there during the timeframe of THD, since they are apparently warmer climate dragons they're probably more populated in tropical/temperate areas like South/Southeast Asia, and the like, plus with sights of people riding dragons the people outside Scotland (which is were Berk is based on iirc) it wouldn't be impossible for people to try and tame dragons and even breed them.
Breeding Night Furies with other dragons just to see what outcome and Pygmy Furies came to be, people thought that they were cute and manageable so they bred for more. They are the size of house-cats
These guys still have the bones where the wings would go.
(These are free to make if anyone wants to)