It was a well known fact amongst Dragons that once every two hundred and fifty years, on a night like the one Toothless was looking up at, a single Dragon could become a human for a year if they so did desire.

When Toothless didn't manage to sleep, because of his insomnia, he could have never expected that his boyfriend would knock at his door, in the middle of that rainy night.

In the Viking village of Berk, any and all minor cuts went unaddressed and wholly unnoticed. For this, Hiccup was grateful.