The 2003 film adaptation of the book has an unusually staggering amount of adult content that got by, to the point where the Seuss estate expressed their disapproval over their inclusion and sparking a debate among critics and audiences over whether or not the movie should've kept its PG rating. It got so bad that they declared that there should be no more live action adaptation of Seuss' works.
- The S.L.O.W. (Super Luxurious Omnidirectional Whatchimajigger)'s original acronym was the Super Hydraulic Instantaneous Transporter (S.H.I.T.), which Conrad is about to spell out until being cut off by the Cat. "OH! Quick! To the S.L.O.W.!"
- Conrad puts a loaf of bread between his trousers before doing the "Indoor Stair Luge".
- This bit with Larry and Conrad confronting each other:Lawrence "Larry": It's Lawrence, you snot-nosed little son of a [Joan walks in] WONDERFUL WOMAN who I'm ABSOLUTELY crazy about!
- Don't forget: "SON OF A BI-(cue Sound-Effect Bleep)" after the Cat (as a chef) cuts off his tail during an argument with a TV show host (who is also the Cat himself). Most TV edits cut out the "BI-" part and mute the bleep.
- Before Quinn's television set is repossessed as a result of a missed payment, it appears that he enjoys watching pornography (seeing the suggestive behavior of the woman on the television).
- When the kids ask the Cat where he came from shortly after his introduction, he takes it...a little too literally:The Cat: Hmmm...How do I put this?... When a mommy cat and a daddy cat love each other very much, they decide that--The Cat: My place, where else?
- When the Cat is singing the fun song:There was this cat I knew, back home where I was bred,
He never listened to a single thing his mother said,
He never used the litterbox, he made a mess in the hall,
That's why they sent him to a vet and cut off both his ba- *pauses* ...ba...ba...BOY!
- And another verse from a deleted scene:There was a high-strung cat, who thought she knew it all,
And when she schedules out her day, it could drive you up a wall,
She likes to be the teacher's pet, always the head of the class,
It took a ton of TNT to kill the bug up her aaaaaaaaaaaaaa...aaaaaa...aaaaaaaaaa... ASK me was she fun, fun, fun?
- And another verse from a deleted scene:
- An extreme example is when the Cat's hat is squashed and crooked, but then he looks at a picture of Sally and Conrad's apparently attractive mother, and his hat SHOOTS UP with an audible *BOING* sound!! How did that get past?! "Although those drapes are a train wreck."
- A deleted scene took this Up to Eleven when, during the scene where he, Conrad and Sally go after Nevins, he literally shows the audience the very picture he saw for a few seconds while sitting on a flowing pool chair.
- While Conrad and Sally are signing the Cat's contract, they briefly go to one page... to see a "spayed and neutered" certificate. The Cat promptly takes said certificate and hides it, declaring, "This is nothing!"
- While disguising himself as piñata, the Cat gets hit in the groin by a burly boy carrying a huge baseball bat. The scene then cuts to him swinging on a swing set, dressed like a girl with a unicorn in the background before cutting back to the Cat, screaming in agony. According to the DVD commentary, it was supposed to be the Cat's "happy place".
- When this scene got by, it was clear that the censors weren't even trying anymore. The Cat calls a gardening hoe a "dirty hoe", leaves it alone and picks it up back and says "I'm sorry, baby. I love you!" Naturally, this was also cut in most television edits.
- When Conrad and Sally see the bathroom toilet shooting out flames while riding Ms. Kwan, the Cat comments that the two might want to "hold it for a little while" and that "Something like that really burns my AaaaaaaHHHHH!" right as Ms. Kwan reaches a drop in the track.
- The song choice for the cleaning montage at the end of the film is a Smash Mouth cover of The Beatles song "Getting Better". It uses a musical interlude for the 3rd verse. No wonder, when the lyrics of the original song were as follows:I used to be cruel to my woman
I beat her and kept her apart from the things that she loved
Man I was mean but I'm changing my scene