Cottonmouth

The cottonmouth is a venomous pit viper that lives in the southeastern United States. It's one of the few vipers comfortable in water, often found near lakes, marshes, and slow-moving streams. When threatened, it coils up and shows its white-lined mouth as a warning.

• Swims well and sometimes crosses between islands and the mainland.
• Displays its pale mouth when feeling threatened.
• Lives near water but can deliver a dangerous bite if disturbed.