That's Kanjigar the Courageous. The troll warrior. They say he slew many monsters who oppose him. Do I believe it? Yes, yes I do.
„
~ Hiccup introducing Kanjigar in his narration
Kanjigar is a minor character in How to Train Your Dragon(My Version) and a flashback character in How to Train Your Dragon: The Hidden World(My Version). He was the mentor of Hiccup and the father of Draal.