Watersnake: was hanging around in the runoff of a spring where I filled a jug with water. When I poked at him he'd puff up - his whole body would become bigger as if I'd stuck an air hose in him. It startled me too. I've never seen a snake do that before. Tried to take a picture of him puffed up but he unpuffed as soon as I left him alone long enough to take the picture.