Simplify the following text for a Grade 9 native English-speaking person.
Original: Kermit the Frog is puppeteer Jim Henson 's most famous Muppet creation , first introduced in 1955 . He is the protagonist of many Muppet projects , most notably as the host of The Muppet Show , and has appeared in various sketches on Sesame Street , in commercials and in public service announcements over the years .
Simplified: Kermit has appeared on many TV shows including Sesame Street , The Muppet Show , Sam and Friends , The Ed Sullivan Show , and Muppet Babies .