When Ozzy infiltrates a meeting of germs at The Zit, he makes mention of a pathogen named Mad Cow who's performing in an upcoming pro-wrestling event. The intended reference was to Mad Cow Disease, specifically the prion that causes it. As the commentary notes, the writers found out that Mad Cow is the name of a real wrestler (he performed on the European circuit from 1995-2006).
Beam Me Up, Scotty!: For reasons unknown, some people associate the phrase "ladies and germs" with this movie.
Box Office Bomb: With a gross of $14,026,418 against a $75m budget, Osmosis Jones was one of the more expensive bombers from 2001. Fortunately, it recouped its losses on home video and WB even allowed its TV show spin-off to happen.
Colbert Bump: The film received a major resurgence 20 years later no less, due to the COVID-19 Pandemic, mostly because the main villain is a virus that tricks Frank's body to think it's a common cold until it becomes fatal.
Creator Backlash: In a 2017 interview with Hannibal Buress, Chris Rock admitted that the film didn't turn out as well as he'd hoped and believed that, in hindsight, it would have worked better as a fully live-action movie, as the Farrelly brothers' style of comedy doesn't really lend itself well to animation.
Defictionalization: There's a throwaway line about the "National Chicken Wing Festival" in Buffalo, New York. There was no such festival at the time the film was made, but they went and made one specifically because of it, complete with wing eating contest and "Miss Buffalo Wing" competition."
Ozzy and Drix move to See World, which is the eye as the earlier explained to Drix about Frank.
Inside the nose, Frank was picking it as Ozzy and Drix find a place to be secure from the finger.
Ozzy and Drix drive to the Heartburn lane as Frank burped so they could go to the uvula. This version has the word "hell" used instead of "heck" as in the final cut.
Executive Meddling: The movie was originally planned to be PG-13, but almost all of the swearing, a scene of Ozzy visiting sperm cells, and several more violent scenes were cut or dubbed over to be more kid friendly. This is considered by fans to be the worst decision made in production. Some have questioned on what the movie would have been if it was PG-13. Some have believed that Warner Bros had trouble on deciding to market this as an animated comedy for adults or an animated kids' movie.
Genius Bonus: They visit the Chicken Pox virus at one point. Varicella zoster, the virus that causes chicken pox, can linger in the human body for years and cause shingles in some adults.
Screwed by the Network: Warner Bros. couldn't figure out if the movie was a family film or an action buddy cop film, so they just dropped it to an August weekend to ensure its failure.
Star-Derailing Role: This movie and Pootie Tang did Chris Rock's acting career no favors. Bar the Madagascar franchise, most of his acting roles since have been in films he's conceived and directed himself.
Throw It In!: When Ozzy comes back from The Zit, he accidentally calls Leah "Brandy" before quickly correcting himself. Chris Rock flubbed his line, having briefly forgotten that he wasn't talking to Leah's voice actress Brandy Norwood, and this made it into the finished film because the director thought it was funny.
Troubled Production: Surprisingly (giventhe studio'strack record) not the case for the animated sequences (that were finished ahead of schedule) but more for the live-action sequences which had no director or a star actor and it took a considerable amount of time acquiring both, until fairly late into production when Bill Murray was cast and the Farrelly brothers stepped in to direct. This was also one of the reasons the film was delayed from its summer 2000 release to the summer of next year.
In the original script and in early cuts of the movie, a scene was featured when Osmosis and Drix go to the Gonad's Gym. It involved them talking to the "exercising" sperm cells. The scene was cut in order to stay family friendly. The Gonad's Gym logo does appear on Drix's suitcase during a scene in the police station locker room.
Also, the script reveals that Osmosis went to a family reunion when he was young. At that time Frank went to the doctors to have some blood removed, possibly in a blood drive. The needle drew out all of Ozzy's relatives, apparently leaving him all alone, which adds to his lone wolf status in the film. The ending has Frank getting a blood transfusion to save his life, with his own prior blood. And Ozzy's family returned to Frank, in a parody of the returning abductees in Close Encounters of the Third Kind. This was revealed in the DVD commentary.
In an early press release and promotional reels, Frank was a construction worker instead of a Zoo keeper.
Will Smith said he was interested in the role of Osmosis, but schedule conflicts prevented that.
According to this long series of pictures, had the film not bombed, there would have been a surge of merchandise based on the movie such as Toys, T-shirts, key chains, and oddly enough, a snot slingshot that shoots fake boogers.
After this movie the Farrelly brothers were going to direct an adult comedy film Party Animals for 20th Century Fox based on the novel Frisco Pigeon Mambo by C. D. Payne with Seth MacFarlane as the head writer but due to the box-office failure of this film the idea was scrapped.
◊ points out, Pikachu makes a split-second cameo in a crowd scene. There actually is a protein called Pikachurin
