Sea-serpents can be found in all major oceans and seas. The sizes and presumed breeds of sea-serpents vary across the globe, but the general body structure argues for a common evolutionary ancestor with dragons. The Chinese refer to the creatures as kiao, or sea-dragons.
Whilst carrying Temeraire and William Laurence to China in 1806 HMS Allegiance was attacked in the Indian Ocean, by the largest sea-serpent recorded by Europeans. The creature was at least 250 feet in length, over twice the size of a Regal Copper, though the body was less than 20 feet in diameter. Although Laurence thought the sea-serpent's eyes showed a lack of intelligent consciousness, Temeraire instinctively felt that the serpent was a sentient creature and was disturbed by his inability to communicate with it and by the eventual necessity to kill it.