Dr. Rick Marshall
Holly Cantrell
Will Stanton
Chaka
Enik
Matt Lauer
Tar Pits Kid
Teacher
Teenager
Teenager (as Jon Kent Ethridge II)
Ernie
Elder Pakuni
Ice Cream Man
Stage Manager
Sleestak
Pakuni Woman
Astronaut (voice)
Library Skull (voice)
The Zarn (voice)
Background Sleestak
Background Sleestak (as Danko Iordanov)
Sleestak (as Tommy Ruddell)
Tar Pits Kid (uncredited)
Sleestak (uncredited)
Background Sleestak (uncredited)
Sally - Barry's Wife (uncredited)
Barry (uncredited)
Boy in Museum (uncredited)
Astronaut (uncredited)
Science Class Student (uncredited)
Statue (uncredited)