3) No More Dragons
The How To Train Your Dragon movies are actually loosely based on a children’s book series by British author Cressida Cowell, which take the form of humorous guides to training dragons (hence the title). There’s little in common with the two iterations apart from a few names and concepts, but this looks to change in the third movie as Dragon 3 will borrow an important detail from the books: dragons are thought to be extinct.
“We’re gonna take the story to where the books begin, which is Hiccup as an adult reflecting back on a time where there were dragons, suggesting that the dragons will in some way go away,” Deblois has explained. “Why and could they come back and the mystery of what all that is will be saved for the actual story.”
Just what causes the dragons to disappear is the big question here. As this is a family movie, we’re guessing that it won’t deal with the species being completely wiped out, but rather some event will probably cause them to go into hiding. Maybe the conflict between Hiccup and Toothless gets so heated that a full-scale dragon vs. human war breaks out?