Characters played by Ross Bagdasarian Jr.
Alvin
Simon
David Seville
Characters played by Janice Karman
Theodore
Tommy's Sister
Cindy Lou
Characters played by June Foray
Mrs. Waterford
Mrs. Claus
Characters played by Frank Welker
Santa Claus
Doctor
Characters played by Charles Berendt
Clyde Crashcup
Characters played by R.J. Williams
Tommy Waterford