This is Colleen Haskell's debut as an actress after being one of the final contenders in the first season of Survivor (2000). Rob Schneider said that working with Haskell was one of the unexpected pleasures of making the film.
In June 2001, Newsweek revealed that print ads for at least four movies released by Columbia Pictures, including this one and A Knight's Tale (2001), contained glowing comments from a film reviewer who didn't exist. The fake critic, "David Manning," was the friend of someone who worked in Columbia's advertising department, and agreed to let his friend use his name. Manning was misrepresented as a reviewer for the Ridgefield Press, a real-life weekly paper out of Ridgefield, Connecticut.
The newspaper clipping of Marvin's father features the face of Rob Schneider's actual father, Marvin (to whom the movie is dedicated) photoshopped onto a police officer. Also, the car in which the lead character has his road accident was originally owned by Marvin Schneider (although several duplicates were also used in the crash sequence).
In both audio commentaries on the Uncut version of the DVD, it is mentioned that Harry Dean Stanton played the part of a hunter staking out the Man-Beast in the forest, but nearly all of the footage ended up on the cutting room floor. He can still be seen, uncredited, being attacked in once scene after Marvin asks Rianna to tie him up.
When Marvin is messing around with Sergeant Sisks shotgun, he accidentally makes it go off shooting his coffee mug and drenching his picture, foreshadowing later in the movie when Marvin has animal abilities and saves the Mayors son from drowning, he splashes around in the water ultimately drenching Sisk.