24 Jun 2008, Washington, DC, USA --- The foot of a living Trichobatrachus robustus frog, which is one of the 11 species of African frogs, shows the white bony claws protruding from the tips of the toes in this undated handout photo. At least 11 species of African frogs carry a built-in concealed weapon -- they can sprout claws on demand to fight off attackers. --- Image by © Courtesy of Harvard University/Handout /Reuters/Corbis
