According to the first book of the series on which this show is based, only the tribe leader and his son are allowed to own a Monstrous Nightmare dragon. Snoutlout owns one because he is the son of Stoick's brother Spitelout and feels that they are the better and obvious choice to be tribal leader and heir. Snoutlout's dragon is named Fireworm, however, and one of Stoick the Vast's two hunting dragons is named Hookfang.
The lullaby that snotlout sings to the baby fireworm dragon is derived from the lullaby baa baa black sheep .