As described in the Book of Job:
'His snorting throws out flashes of light; his eyes are like the rays of dawn.
Firebrands stream from his mouth; sparks of fire shoot out.
Smoke pours from his nostrils as from a boiling pot over a fire of reeds.
His breath sets coals ablaze, and flames dart from his mouth.'
Actually that all sounds quite cool! - but it's also a general term for something large and lumbering, which seems to be given to things like big boats and planes and fictional spaceships, and not so much little boys.