Sea snakes have a flat body and a tail that looks like a paddle from the side. Like cobras, they are poisonous snakes with front groove teeth. Common sea snakes are black and white, but there are many different kinds of sea snakes, and different kinds of sea snakes have different colors. They look similar in appearance to eels, and they all live in seawater. Although they live in seawater, they all breathe through their nostrils, so they need to swim to the water regularly to take a breath to ensure that they can breathe normally.

Sea snakes are poisonous, and their venom is the strongest animal poison. The venom of hook-billed sea snake is twice as toxic as cobra venom and 80 times as toxic as sodium cyanide. The venom of sea snakes is different from that of cobras. Although they are both neurotoxic, the main part of human body they damage is voluntary muscles, not nervous system.

Sea snakes bite without pain, and venom also has incubation period. After being bitten by sea snakes, there will be no obvious poisoning symptoms for about 1-3 hours. But after incubation period, the venom will begin to spread, and poisoned people will feel muscle weakness at first. As time and venom spread, they will have symptoms such as soreness and ptosis. However, this symptom is similar to tetanus, and many breeders can't distinguish it in time. But if the toxicity is too deep, the heart and kidneys will be damaged, and death will occur in the most red cases.