"Prickly is Leaving" is the first segment of the fortieth episode of Recess.
Principal Prickly gets his wish of being a middle school principal but his replacements, an evil man named Dr. Slicer and his assistant Gilda, are even worse.
During one of the day's recesses, Prickly gets a call: Superintendent Skinner has a middle school principal position open at Spiro T. Agnew as the previous principal was "fired." Prickly has an open application for positions such like this and hence is offered the job; Prickly is overjoyed - but not as much as the students who welcome a break from him. However, Miss Finster is not happy, because she and Prickly have been best friends after all these years.
After discussing their plans on what they would do after Prickly left, Menlo - who was with Miss Lemon and Prickly outside of his office - responded to the gang. He was not initially phased - until he read a fax letter that arrived in the office, however. That's because it read that Prickly's replacement is an even worse man known only as "Slicer."
Slicer and his assistant Gilda visit, instantly he sorts the schools "problems" and encourages more Discipline. While T.J. initially tries to butter up to the new Principal, Slicer is offended by T.J'.s plans at niceties; frightens him; orders him to take off his hat and gives him a humiliating paper hat to wear.
After Dr. Slicer's visit, T.J. decides that he and his gang must do everything they can to stop him becoming Principal. The gang realizes the only way to retain Prickly is to convince him to not leave. Attempt one involved them broadcasting a fake news broadcast in Prickly's office to portray the school as dangerous, but Prickly immediately dismisses the credibility as he only concerns the problems with middle school students.
Finster, however, organizes a school-wide farewell celebration. While Skinner is impressed with the exposition, the gang's next plan to derail Prickly's promotion to Middle School is to portray themselves as Middle school students with all the subsequent problems a principal might have to live with. However their plan fails once again; finally T.J. gives a heartwarming speech to Prickly just before he leaves. Prickly is touched, but Slicer is not amused, and he makes T.J. wear a paper hat that says "Captain. Sappy" (earlier Slicer made T.J. wear a hat that said "Funny Boy".)
Outraged by this, Miss Finster confronts Dr. Slicer for this, but he shouts at her. He immediately appoints his assistant, Gilda, to Miss Finster's position, making her Gilda's assistant. He also plans to tear down the jungle gym in order to make room for a guard tower and that he was to restore the cannon in the front of the school operational.
The next day, everyone prepares for Slicer while T.J. panics over which hat Slicer wanted him to wear. However, Prickly comes back and Slicer is heard protesting but Prickly dismisses him. Prickly claims that the Superintendent would not "cough up" enough money for the job at Spiro T. Agnew, and decides to stay at Third Street until "they make a better offer". But the final shot, in which Prickly smiles as the kids cheer at his decision to stay, gives plenty of implications for why he didn't accept the job as middle school principal.