What actors and actresses appeared in Casper Meets Wendy - 1998?

The film you are referring to is actually called "Casper: A Spirited Beginning", not "Casper Meets Wendy" (although there is a "Casper Meets Wendy" short film).

Here are the main actors and actresses in "Casper: A Spirited Beginning":

* Casper: Christina Ricci

* Kat Harvey: Hilary Duff

* Dr. James Harvey: Bill Pullman

* Ghostly Trio (Stretch, Stinky, and Fatso): Joe Nipote, Brad Garrett, and Joe Alaskey

* Spooky the Ghost Dog: (voice) Joe Alaskey

* The Carrigan Sisters (Margaret, Megan, and Molly): Kath Soucie, Tress MacNeille, and Cree Summer

This film is a prequel to the 1995 "Casper" film and shows Casper's early life as a ghost.