The PBS animal documentary Nature: Supersize Crocs begins with an incredible legend. Amid worldwide terror over the cannibalistic proclivities of the crocodile, even more jolting rumors persist of an oversized species that allegedly spans up to 21 feet. On a heartbreaking note for zoologists everywhere, this variant of croc -- a carryover from ancient times -- may soon cease to exist. Determined to locate this dying branch of the crocodile family, naturalist Romulus Whitaker hearkens off to Australia, Northern India, and Ethiopia, where the skin of a 21-footer recently cropped up; once there, he begins to search the homes of the Nile, Saltwater, and Gharial crocodile families with the hope of locating the extinct or near-extinct 21-foot breed. Celebrated Oscar-winning actor F. Murray Abraham (Amadeus, Mighty Aphrodite) narrates.