Honestly their characters are so fundamentally similar and different its amazing
Also kinda funny that book!hiccup is the one who values kindness despite killing dragons WAAAYY more frequently than movie!hiccup
I think that's actually really important because book!hiccup strives to be kind despite the cruelties he has seen and has had to commit.
Movie hiccup has remained curious despite the danger that curiousity puts him in.
He learned about dragons out of curiousity, not thinking of how dangerous dragons can be when you get too close.
Book!Hiccup learned about dragons out of compassion in wanting to learn about others, not thinking of how that would alienate him from his tribe further.
Movie hiccup is more proactive, making plans before bad things happen,
Book hiccup is more reactive, putting off thinking of bad things until their on top of him, this is honestly out of blind optimism.
WHICH IS ALSO UNTERESTING CUZ OF THEIR DYNAMIC WITH TOOTHLESS
in the movie, because hiccup makes plans ahead of time, he doesn't mind getting into trouble as much, and then toothless has to get him out of it.
In the books, Hiccup doesn't want anything to do with dangerous stuff, he is more of an avoider if there isnt a reason for him to do smthn so most of the time, its toothless getting to trouble and hiccup having to get him out of it.