The first time Frankie Muniz didn't provide Chester's voice. He was replaced by "Kid" voice actor' Jason Marsden'.
All the magical creatures who attend Timmy's party are from earlier episodes of the series: Tooth Fairy, Santa Claus, The Easter Bunny, The April Fool, Wandisimo and Jorgen Von Strangle.
When Timmy introduces himself to Crocker as "The World's Greatest Entertainer", wearing a Groucho Marx mask, Crocker refers to him as "Shemp", mistaking him for Shemp Howard, the fourth Stooge, and using the term to mean someone who is a body-double or stand in.
Although this TV movie premiered in 2003, it was produced in 2002 according to the credits.