Richard Marshall Eakin (/ˈeɪkɪn/ AY-kin; May 5, 1910 – November 25, 1999), was an American zoologist and professor at the University of California, Berkeley. He was widely known for portraying prominent historical scientists during some of his lectures; dressing in costume and speaking in character to entertain and inform his students. A 1953 Guggenheim fellow, he wrote several books and more than 200 scientific papers. His research focused on eyes and vision in animals, especially the parietal eye or "third eye" of vertebrates, as well as animal embryology. He served as chairman of the UC Berkeley Department of Zoology for over 10 years, was elected president of the Western Society of Naturalists and American Society of Zoologists, and was a fellow of the California Academy of Sciences.