Bork the Bold

 Bork the Bolder (formerly known as Bork the Very, Very Unfortunate) was the great-great-great-grandfather of Gobber the Belch, and (in the film continuity) was the writer of the first Dragon Manual.

His backstory is related in Book of Dragons; Over the course of his life, Bork attempted many professions, but was always sabotaged by passing Dragons. Over the years, Bork accumulated a lot of knowledge about Dragons, writing the information down in a book. It was Bork who created the Dragon "Classes", such as Strike, Fear, ETC. His work was passed down and modified through the many Viking generations of Berk. His gathering of Dragon knowledge in spite of the risk to his own life merited his change of title.