Rooney Haddock ( book2 of Hiccelsa)

Ride back to Berk were Hiccup and Elsa are well they rules . Journey with there daughter, Rooney. Were she find a new island, Night Furry island. So, Rooney and Nevermore her Night furry go to see how the Night furries disappeared. But there is one secret that she keeps hidden, a strange mark on her arm that looks like a human with a tail and wings. She is still trying to figure out what it means.

By the way I'm adding Jardia to this book. Well Hiccup and Jack don't really get along but , there kind of friends.