Meanwhile, deep in the ocean, but not so very far from the Isle of Berk, a real Sea Dragon such as Old Wrinkly had been describing lay sleeping on the sea-bed. He was indescribably large. He had been there so long that he almost seemed to be part of the ocean floor itself, a great underwater mountain, covered in shells and barnacles, some of his limbs half-buried in the sand.
Generation after generation of little hermit crabs had been born and had died in this Dragon's ears. Hundreds and hundreds of years he'd slept, because he'd had rather a large meal. He'd had the luck to catch a Roman Legion camping on a clifftop -- they were completely cut off and he had spent an enjoyable afternoon wolfing down the whole lot of them, from commanding officer to lowliest private. Horses, chariots, shields, and spears, the entire lot went down the ravenous, reptilian gullet. And, while things such as golden chariot wheels are an additional source of fiber to a Dragon's diet, they do take some time to digest.
The Dragon had crawled down into the depths of the ocean and gone into a Sleep Coma. Dragons can stay in this suspended state for eternity, half-dead, half-alive, buried under fathom after fathom of icy-cold seawater. Not a muscle of this particular Dragon had moved for six or seven centuries.
But the previous week, a Killer Whale who had chased some seals unexpectedly deep was surprised to notice a slight movement in the upper eyelid of the dragon's right eye. An ancestral memory stirred in the whale's brain and he swam away from there as fast as his fins could carry him. And, a week later, the sea around the Dragon Mountain -- which had previously been teeming with crabs and lobsters and shoals and shoals of fish -- was a great, underwater desert. Not a mollusk stirred, not a scallop shimmied.
The only sign of life for miles and miles was the rapid jerking of both the Dragon's eyelids, fluttering up and down as if the Dragon had suddenly gone into a lighter sleep and was dreaming who knows what dark dreams.