Steve Whitmire
Kermit the Frog / Rizzo the Rat / Beaker / Elvises (voice)
Dave Goelz
The Great Gonzo / Dr. Bunsen Honeydew / Waldorf / Zoot (voice)
Bill Barretta
Pepe the King Prawn / Bobo the Bear / Johnny Fiama / Swedish Chef / Lew Zealand / Howard Tubman / Rowlf the Dog / Elvises (voice)
Eric Jacobson
Miss Piggy / Fozzie Bear / Animal / Yoda / Elvises (voice)
David Arquette
Daniel
Joan Cusack
Rachel Bitterman
Matthew Lillard
Luc Fromage
William H. Macy
Glenn
Whoopi Goldberg
Daniel's 'Boss'
Mel Brooks
Joe Snow (voice)
Carson Daly
Self
Molly Shannon
Self
Chantal Strand
Nancy Nut-What
Dave 'Squatch' Ward
Sally Ann Santa Claus
Brian Henson
Scooter / Janice / Sal Minella (voice)
Kevin Clash
Sam Eagle (voice)
John Henson
Sweetums (voice)
Jerry Nelson
Robin the Frog / Statler / Announcer / Pops / Floyd Pepper
Allan Trautman
Eugene the Tuba Player (voice)
Drew Massey
Muppet Performer
Zach Braff
Dr. John "J.D." Dorian
Sarah Chalke
Dr. Elliot Reid
John C. McGinley
Dr. Perry Cox
Judy Reyes
Nurse Carla Espinosa
Neil Flynn
Janitor
Robert Smigel
Triumph, the Insult Comic Dog (voice)
John E. Kennedy
Dr. Teeth (voice)
Colin Foo
Security Guard
Marci Dacus
Fear Factor Contestant (uncredited)