Yesterday, while in the field, I finally caught an animal that previously I'd only seen once, and then only momentarily before it slipped away into murky waters at night. The snake is a Gulf Crayfish Snake (Regina rigida sinicola). As it's name would suggest, it specializes on eating crayfish; specifically ones that have recently shed their hard outer shell. However, it opportunistically eats other things as well, including other aquatic invertibrates, fish, sirens, frogs, and salamanders. This species is probably fairly common, but just difficult to find.