McKean has often worked with his close friends Christopher Guest and Harry Shearer on films including This Is Spinal Tap, A Mighty Wind (for which McKean was nominated for an Academy Award for best song), and For Your Consideration, as well as Guest's Best in Show.
In 1994, McKean became the oldest person ever to join Saturday Night Live as a cast member. Other television work includes guest spots on Lois and Clark: The New Adventures of Superman, Law & Order, Happy Days, Friends, Alias, Smallville (as Perry White), and Star Trek: Voyager.
Broadway shows include Hairspray (as a replacement for Edna Turnblad, a role originated by Harvey Fierstein), and The Pajama Game (with Harry Connick Jr.), while film credits include The Producers, Planes, Trains & Automobiles (with Steve Martin and John Candy), and Clue (with Tim Curry and Christopher Lloyd).
- Dinosaurs: Ansel, Officer Bettelheim, Bryant, Dr. Herder, Guy in Lab Coat, Hank, Inspector, Kyle, Les, Mr. Myman, Parish (all voice only)