I was going to do a oneshot on this, but I changed my mind
So those of you who have read the recent chapter (chapter 3) might have noticed that things are a little different than the way they happened in the movie.
Firstly the dragon battle between Hiccup and the Red Death never happened. Which means that he still has his leg, for now.
Toothless is in this story, he and Hiccup have already met (you all know how that went). Stoick found out abut Toothless, but Hiccup somehow managed to talk him into letting him keep Toothless (I don't know how, even I'm not that persuasive)
Additional info:
I will be writing the Vikings a little bit darke