Why is Kermit the Frog the only Muppet associated with Sesame Street?”
Jim Henson, sold rights to his Muppet characters to Disney. The Muppet show was created after Sesame Street. Almost as a spin off, along with a whole new cast, save Kermit. Since all the other characters were still doing Sesame street, the need arose to find new friends for Kermit. Kermit branched out, into a more comedic arena , as opposed to the more educational format of Sesame Street. The characters are still wholesome, as well as entertaining.None of the other Sesame Street gang “bridged the gap, “as Kermit did. MuppetsOnline.com list the different characters, for the different shows. The one common thread among Sesame Street, The Muppet Show,Fraggle Rock, Bear in the Big Blue house, is that they are all Muppet creations of Jim Henson Productions.
Sesame Street was the first show to use Muppets and Kermit was one of the originals. It was a Public Broadcasting System show (called “Educational Television” in those days, the late 60s). Many of the characters were muppets: Grover, Cookie Monster, Oscar the Grouch, etc. The Muppet Show came later (mid 70s) as a commercial spin-off with a host of new characters like Ms. Piggy and Fozzie Bear. Kermie was the only one to make the jump to the new format.