I have no idea. But to me, the movie version is better. He's more aggressive yet still gentle and protective of Snotlout, he's big enough to ride, [the book version was the size of a leoppard] though he does have a 'don't-listen-to-whatever-Snotlout-tells-me-to-do' attitude, he still loves Snotlout as seen on Gift of the Nightfury and Riders of berk episode 2.
He is a good dragon