Phixius

Corrected entry: In the first movie and beginning of the second, Hiccup is left handed. But when he shoots the arrow at Stoig's burning ship, he is a right hander.

Corrected entry: In the first movie Hiccup receives his horned helmet from his father, made from his mother's breastplate. His mother is actually very small in this movie though, so the breastplate-helmet could not have been from her.