LOFTER old article, first published on 2016.12.27
Original works: How to Train Your Dragon, The Guardians, Harry Potter
Classification: All ages
Warning: To understand the plot, you need to read the original Order of the Phoenix
Pairing: Jack Frost xHiccup/Frostcup/Hijack
If it wasn't Grawp who came to save Harry and Hermione.
Dragon Training/Guardian/HP original setting crossover. Although it was originally said to be the same setting as "The Roaring Letter", Professor Hiccup couldn't keep up his imagination... So this became this article. The plot has nothing to do with "The Howling Letter".
Similarly, in order to unify the style of the article, Hiccup Haddock=Hiccup Haddock/Hiccup Haddock, Hic (nickname)=Hiccup, Hiccup the Useless=Waste Hiccup, Jack Frost=Jack Frost, Toothless=Toothless. North=North. HP uses humanistic translation.
Conception:
[Naruzuo Toizumi] Ghost