Voice cast
• Sam Rockwell as Darwin the Guinea Pig, the team leader of G-Force.
• Penélope Cruz as Juarez the Guinea Pig, the team's martial arts specialist.
• Tracy Morgan as Blaster the Guinea Pig, the team's weapons and transportation specialist.
• Jon Favreau as Hurley the Guinea Pig, an overweight guinea pig who becomes the newest member of the team.
• Steve Buscemi as Bucky the Hamster, a stubborn hamster at the pet store who also becomes a new member of the team.
• Nicolas Cage as Speckles the Star-Nosed Mole, the team cyber intelligence expert and the main antagonist.
• Dee Bradley Baker as Mooch the Fly, the team's reconnaissance scout.
Live-action cast
• Bill Nighy as Leonard Saber
• Will Arnett as Kip
• Zach Galifianakis as Ben
• Kelli Garner as Marcie
• Niecy Nash as Rosalita
• Loudon Wainwright III as Grandpa Goodman
• Tyler Patrick Jones as Connor Goodman
• Piper Mackenzie Harris as Penny Goodman
• Chris Ellis as FBI Director
• Gabriel Casseus as Carter
• Justin Mentell as Terrell
“No Animals Were Harmed”®
Specially trained, genetically engineered guinea pigs discover a plot by an evil mogul to rule the world using household gadgets. The animals set out to stop the villain’s plot while hiding from the government agents who want their special ops project shut down.
Featured Animal Action
The set was only open to limited cast and crew members, and they were introduced to the animals and instructed on their proper handling before filming began.
Computer-Generated Animals
Mooch the fly, Speckles the mole, the snake attacking the glass, the tarantula, the hamster, the worm fed to Speckles, the cockroaches and the guinea pigs were all computer-generated, except for the few guinea pig scenes described below.
Guinea Pig Live Action
In a couple of scenes, real guinea pigs were filmed (such as at the pet store), and used for “establishing” shots before showing the computer-generated versions. Whenever real guinea pigs were filmed, trainers placed them on their marks and either cued the action or allowed them to do whatever came naturally. The actors were extremely well-rehearsed and instructed on the guinea pigs’proper handling.
The material seen at the bottom of the cages was their natural bedding. For the scene in which Connor (Tyler Patrick Jones) picks up a guinea pig and holds it upside down, the actor was instructed on how to gently hold the guinea pig for a brief moment. When Connor places the guinea pig into a net and catapults it into the snake and spider cage, trainers instructed the well-rehearsed actor on how to carefully place the guinea pig into the net. There were padded mats below in case the guinea pig fell, which it did not. The rest of the scene, including the pig launching into the air, involved a computer-generated guinea pig, snake and spider.
Pet Store Animals
A chameleon, rats, birds, puppies, dogs, cats and rabbits were placed in their respective cages, perches or aquariums and allowed to do whatever came naturally. They were separated according to species. All temporary housing was inspected, secured and made comfortable before filming began. Several off-camera trainers stood nearby. Snakes, lizards and frogs seen in cages were rubber props.