Many sperm whales stranded on beaches or caught by whalers exhibit telltale circular scars like these. Only one thing could have made them: the strong suckers that line the giant squid’s eight arms and two long feeding tentacles. Older sperm whales have so many scars that they overlap each other. Learn more about the over-sized anatomy of the giant squid in this video with Smithsonian scientist Dr. Clyde Roper. More about the giant squid can be found in our Giant Squid section.