Kermit is a puppet: a bright green frog with long legs, a wide mouth, and a gentle, slightly worried voice. He is often called Kermit the Frog. Jim Henson made him, and he is one of the main characters in The Muppets and, for many years, on Sesame Street. He sings, he tries to keep the show together, he gets into trouble with Miss Piggy, and children all over the world know his face. Kermit was already a real person's name; it became well known in the United States partly because of Kermit Roosevelt, named after a Manx ancestor. The frog came after that, and then made the name famous in a completely different way. Though actually, there is also an old computer file-transfer system called Kermit, named after the frog. Later people invented a stiff official-sounding expansion for the letters, but that was a story made up afterwards, not the real naming. When students meet Kermit in English class, they almost always mean the frog.