The copperhead snake ("Agkistrodon contortrix") is a species of venomous snake. It lives mainly on the eastern coast of North America and in the Mississippi drainage. They're common. Compared to others they're more likely to bite if they feel threatened. They're medium sized. One of the longest ones ever recorded measuring a little more than four feet long. The copperhead is venomous, but its venom is rarely fatal to humans.