Tom McGrath as Skipper (voice)

Chris Miller as Kowalski (voice)

Christopher Knights as Private (voice)

Conrad Vernon as Rico (voice)

John Malkovich as Dave (voice)

Benedict Cumberbatch as Classified (voice)

Ken Jeong as Short Fuse (voice)

Annet Mahendru as Eva (voice)

Peter Stormare as Corporal (voice)

Andy Richter as Mort (voice)

Danny Jacobs as King Julien (voice)

Werner Herzog as Documentary Filmmaker (voice)

Sean Charmatz as Cricket (voice)

Billy Eichner as New York Reporter (voice)

Stephen Kearin as Pilot / Aquarium Employee (voice)

Ava Acres as Girl at Zoo (voice)

Kelly Cooney Cilella as Mermaid Penguin (voice)

Susan Fitzer as Antarctic Penguin (voice)

Chris Sanders as Antarctic Penguin (voice)

Emily Nordwind as Antarctic Penguin (voice)

Mike Mitchell as Antarctic Penguin (voice)

Hope Levy as Antarctic Penguin / Woman at Aquarium (voice)

Walt Dohrn as Antarctic Penguin (voice)

Jim Pirri as Gondolier (voice)

Elizabeth Pan as Shanghai TV Reporter (voice)

Jeff Fischer as Security System Voice (voice)

Stephen Apostolina as Penguin Prisoner (voice)

Al Rodrigo as Penguin Fan (voice)

Steve Alterman as Aquarium Announcer (voice)

Carter Hastings as Boy at Aquarium (voice)

Cullen McCarthy as Boy at Zoo (voice)

Nicholas Guest as Flight Attendant (voice)

Adriano Aragon as Angry Man (voice)

Lynnanne Zager as Computer Voice (voice)

Angie Wu as Girl with Snow Globe (voice)