Steve Whitmire — American Entertainer born on September 24, 1959,

Steven Lawrence "Steve" Whitmire is an American puppeteer, best known for being the performer of Kermit the Frog and Ernie—roles he inherited after Jim Henson's death in 1990. Whitmire has been with the Muppets since 1978, performing a variety of characters on The Muppet Show, Sesame Street, and Fraggle Rock series and during such occupations has worked for the Jim Henson Company, Sesame Workshop, and Disney's The Muppets Studio... (wikipedia)

Henson had never spoken to me about Kermit, but he had spoken to Frank Oz about the idea of me doing the character if he became too busy. I felt flattered.
The thing that got me closest to doing Kermit was remembering what Jim did when he was doing Kermit. When he would do Kermit, there were certain faces that he made. There was a certain way he stood, a certain kind of body language that he had.