Wayne Knight was the voice of Jack O'Lantern in Billy & Mandy's Jacked-Up Halloween. He was also well known for his roles as Newman in Seinfeld, Evil Emperor Zurg in Buzz Lightyear of Star Command, The Penguin in Harley Quinn, Al McWhiggin in Toy Story 2, Stan Podolak in Space Jam, Mr. Blik in Catscratch, Tantor in Tarzan, Dennis Nedry in Jurassic Park and Dojo in Xiaolin Showdown.