Head and Tail Light Tetra Wallpaper is a free animated desktop wallpaper that brings virtual Head and Tail Light Tetra swimming around your desktop while you work. You will see a school of green fire fish swim closely together and you can put swimming Head and Tail Light Tetra is a lively, colorful and hardy fish, good for beginning aquarists. It gets it's common name from the way two small areas on the body seem to reflect light.