Creator Hugh Wilson wrote this episode in response to CBS's demands that he make the show more farcical and kid-friendly. It was the last episode of the initial 13-episode order, and Wilson was so embarrassed by the finished episode that he used a pseudonym for the writing credit.
While on break from production, Hugh Wilson visited his father who was a law professor at Harvard. Some students from the law class came to visit Wilson and told them they had just seen "Fish Story" and thought it was the most hilarious TV episode ever produced. Even though Wilson "disowned" the episode, he couldn't resist getting a little recognition, so he told the students, "Well, do you want to know something? I wrote it!" One of the students asked, "Well, what's your name?" Wilson replied, "Hugh Wilson." The students got somewhat irate after his reply and one of them added, "You did NOT write it! We saw the credits. Raoul Plager wrote it!"
In the opening credits, Hugh Wilson used the name Raoul Plager. He was under pressure by CBS to write a more broad comedy, and since he did not want to do work that he felt was beneath him, he used an alias. This episode turned out to be the highest rated during the show's run.
One sign of the times in this episode is the use of pay toilets in a public restroom, which by this time was being phased out across the country. Herb, wearing the fish costume needed to use the bathroom badly but had no money and tried unsuccessfully to sneak in a stall by crawling underneath the door when he is caught by the mascot for WPIG coming out of the stall next to him. That mascot slams the door on Herb when he begs to use his stall, then berates him for what he tried to do, sparking practically an all out war between the mascots with Les joining in.