In order to save costs, many of the animals were actually puppets. Brendan Fraser claimed that there was only one scene in the entire film that he actually worked alongside a real animal, that being the scene with the turkey.
Having been in great shape for a number of action movies, Brendan Fraser relished the thought of easing up on his demanding physical regimen and allowing the weight to pile on. Initially, he considered losing it for Furry Vengeance (2010) but then thought it would add to the film's comic appeal if he appeared in it with a "muffin top".
Steve Carell and Jeremy Piven were both attached to play the lead role at various times before Brendan Fraser was eventually cast.