"Man's Best Friend" is the 4th episode of season 2. It is the "banned" episode that John K. attributes to him being fired from the show. It was aired later on Ren & Stimpy "Adult Party Cartoon".
One day, George Liquor is standing outside of a pet store, watching Ren and Stimpy sleep in the window and gets the idea to adopt them as his pets. Upon arriving home, he introduces them to their new abode: a fish bowl from which the fish was rudely thrown out (and stole George's car as a result). The next day Ren and Stimpy awaken to find George Liquor dressed as a drill sergeant to train them to be proper pets. Their first lesson is house training by doing butt-push-ups on a newspaper. Ren fails, but Stimpy easily does his business while reading about mudslides. He is given a cigar-shaped dog treat as a reward. Next they are taught discipline. To learn discipline, first they have to learn to disobey. George Liquor tells them NOT to go anywhere near the couch, then instructs them to do just that so they can be punished. When he begins to become enraged by them not following his orders, Ren freaks out and collapses to the floor sobbing, and a terrified Stimpy hurls himself onto the couch as George had instructed, only to be yelled at. Stimpy is scared, thinking he's going to be punished. Instead, George compliments him for following orders and gives him another dog treat. Then George asks Ren to ask him for punishment. But George insists that Ren is too "soft" for punishment and instead gives him 20 dollars and tells him to take the car and see a movie as well. Ren points out that the fish already took the car and it looks like George is going to be enraged. Instead, he gives Ren another 20 dollars for being a smart mouth.
Lastly, he teaches them go to protect their "master". But before they learn to defend, they have to learn to attack. Wearing a padded suit, he urges the two of them to attack him. Stimpy refuses because George is his "kind and beloved master", but Ren, who is sick of George Liquor and their treatment, picks up an oar and maniacally begins beating him up with it, much to Stimpy's horror. Again, Ren expects George to be enraged. Instead, he is impressed and calls him a champion and produces cigar-shaped treats for all of them. The episode ends with the three of them dancing with the cigar-shaped treats clamped between their teeth.
- "Man's Best Friend" was originally going to air in the second season, but the episode was banned by Nickelodeon for excessive violence (Ren beating up George), reference to tobacco, and several scatological jokes. The episode did not see airtime until the Adult Party Cartoon.
- Spike's official episode lineup on their website considers "Man's Best Friend" a part of the "Adult Party Cartoon", but this episode is not counted as one of the three episodes from this series that did not air in the U.S.
- George, however, was meant to make an appearance in the Adult Party Cartoon, in an episode in which he and the pair go camping, but the episode wasn't produced before the cancellation.
- John K. was hoping this would have been another one of his masterpieces of the season, but due to the scene that caused it to be banned, he failed to do so and was fired by Nickelodeon later on.
- After John K. lost his job, the show still displayed crude humor.
- George Liquor is voiced by Michael Pataki in this episode, who would permanently take on the role until his death.
- Previously, he was portrayed by Harris Peet, who voices Muddy Muddskipper.
- This episode later aired on Spike TV/TNN on Ren and Stimpy's Adult Party Cartoon with the episode Big House Blues with a TV-MA rating.
- The episode title and scene where George Liquor buys Ren and Stimpy are a tribute to Merrie Melodies cartoon Elmer's Pet Rabbit (1941).
- This episode was meant to take place before "Dog Show" as George had apparently trained the duo by that point.