You know this technically isn't a crossover. Hiccup and his family are Vikings. Thor, Loki, Odin etc. are Viking gods. So like all the bad luck on Hiccup could've been Loki messing around. XD How to train your Dragon Norse / Viking Gods
I absolutely love this! For one Nirvana, Metallica, and Green Day are a few of my favorite bands. And I have always hated Justin Bieber and One Direction. But this makes me love Nirvana, Green Day, and Metallica like times more.