If a water snake wanted to be anything in its lifetime, it would be a Cottonmouth. Most of the time, identifying one of these apart from a harmless water snake simply can't be done without getting a close look. They're likely the most successful viper in Louisiana as they are easily the most common. I saw them in multiple different habitats at while I visited. My favorite feature is the very noticeable ridge that makes up their snout. (This is characteristic of basically any moccasin). Like a water snake, they're very flighty and will do anything they can to get out of your way but when cornered, they show you what gives them that iconic name.