I saw a red-headed snake in Maling River, a tourist area. What kind of snake is it?

This red-necked snake is a poisonous snake, and its toxicity is unknown for the time being. Most people think it is a light poisonous snake, that is, a toxin that is harmless to human body. However, some people have been seriously affected by the venom of the red-necked snake, which shows that people's blood coagulation function is impaired and bleeding is endless. At present, there is no anti-venom serum of red-necked snake, and only other medical means can be used to treat coagulation function, and the cost is about 40 thousand yuan (if it is not cured, it will always lose blood and be life-threatening). This is the news I saw on the Internet, and its authenticity needs to be verified. However, since it is so mysterious, it is better to be careful.