Will Ferrell

Dr. Rick Marshall

Anna Friel

Holly

Danny McBride

Will Stanton

Jorma Taccone

Chaka

John Boylan

Enik

Matt Lauer

Matt Lauer

Bobb'e J. Thompson

Tar Pits Kid

Sierra McCormick

Tar Pits Kid

Steven Wash Jr.

Tar Pits Kid

Brian Huskey

Teacher

Noah Crawford

Teenager

Jon Kent Ethridge

Teenager

Ben Best

Ernie

Chris Henchy

Stage Manager

Kurt Carley

Sleestak

Todd Christian Hunter

Sleestak

Marti Matulis

Sleestak

Tim Soergel

Sleestak

Douglas Tait

Sleestak

Ana Alexander

Pakuni Woman

Eve Mauro

Pakuni Woman

Pollyanna McIntosh

Pakuni Woman

Paul Adelstein

Astronaut (voice)

Daamen J. Krall

Library Skull (voice)

Leonard Nimoy

The Zarn (voice)

Michael Papajohn

Astronaut (uncredited)

Kiernan Shipka

Tar Pits Kid

Dylan Sprayberry

Tar Pits Kid (uncredited)

Zach Callison

Tar Pits Kid (uncredited)

Moran Atias

Pakuni Woman