Common thresher sharks are brown, gray, blue-gray, or blackish on the back and underside of their snout. They’re lighter on the sides, and fully white below. Their pectoral, pelvic, and dorsal fins are blackish, and some have white dots on the tips of the pectoral, pelvic, and tail fins. The tail fin is sickle-shaped, and the upper part is extremely long, about half the length of their body.