Mel Gibson: You want me to replace the villain with a dog? I mean nobody will know what's going on. Homer: They will if you set up that the dog is evil. All you do is have to show him doing this. [lowers eyelids and glances around in shifty-eyed fashion] The people will suspect the dog.
Also this episode marks the first time in the entire series that someone actually farts, which most fans has chalked up as yet another sign the show is trying to be crass and in-your-face like South Park (and later, Family Guy).
Hilarious in Hindsight: Given everything that happened to Mel Gibson years after this episode aired makes this episode funnier than it was when it first came on, especially the plot point of Gibson making an overly violent movie that shocks and disgusts his fans (Passion of the Christ).
Pandering to the Base : In-Universe, Homer writes a bad review of his movie so he lets him work on the redit, thinking Homer was saying what people really felt and had the guts to tell him. When in fact it was because Homer is a tasteless boob who skips over any part of a movie thats not funny or action packed.
Take That: One of the executives said Homer's changes made Gibson's movie worse than The Godfather III and Mel Gibson told him not to say that kind of thing. The executive conceded he went too far with the comment but still wanted to destroy Homer's film.
Wacky Fratboy Hijinx: Homer pitches a movie idea to Mel that sounds like the plot to Animal House (or American Pie, since he mentioned "nerdy teens trying to get some," and, at the time, movies like that were making a comeback).