The species of 'One' sea serpent, the 'Belcher' sea serpent, is considered by experts to be the most toxic of all sea serpents. Fortunately, sea serpents are very tame and human casualties are very rare. They breathe by absorbing oxygen directly from the water, through their skin. They also have a special gland on their tongue, which can remove the excess salt from the internal organs.
There's more, perhaps the most amazing of the sea serpents is the Golden Sea Snake (Sea of the Golden Snake). This species can have photoreceptors in its tail, allowing it to detect variations of light and possibly detect predators. That said, Golden Sea Snake can see with its tail.
