Even though he is about as strict as Ms. Finster, he is not megalomaniacal, and he is seen in various episodes as actually caring about the students, but that does not mean he is always nice to them. He has a complicated relationship with the Recess Gang, more notably with T.J.. thanks to the boy's almost constant pranks. His dream is to one day rise up to be a middle school principal, as was stated numerous times in the series, though he stays the principal even after getting a position as one since he realized how appreciated he was at Third Street.
Originally Prickly was hired as a teacher at Third Street but was promoted to principal by accident after he'd informed the district superintendent that his then-best friend and ex-principal Dr. Phillium Benedict was trying to cancel recess in an attempt to stop him. During and after the events of the movie, he was reminded that he'd become a teacher all those years ago to help kids and not for the perks of his job. His cold personality came from Dr. Phillium Benedict.
He is somewhat technologically inept as he can't even operate a VCR, let alone a computer in The Girl Was Trouble.
Prickly is almost always seen with a pink shirt, a green tie, gray or light brown pants, and a black or dark brown tweed suit jacket with a handkerchief in its pocket. He has balding black hair, a noticeable mustache, wrinkles, and he wears glasses just like many of the teachers at Third Street. As seen in Nobody Doesn't Like T.J., he wears a wig and is actually bald.
In his youth, Prickly resembled singer and songwriter John Lennon.
Recess: School's Out
On the last day of school, T.J. uses Gretchen's voice changing device to pretend to be Principal Prickly, telling the students that he has a "fat saggy butt", which the real Principal Prickly doesn't take kindly to. But before he can punish T.J. for his prank, school lets out for the summer. As T.J. leaves Prickly's office, he tells him that he hopes he'll grow up a little during the summer, before expressing self-loathing regarding his job under his breath. When discussing plans for the summer, he makes it clear that he's looking forward to days on the golf course, with T.J. not bothering him at all.
A couple days later, T.J. sees Prickly leaving a golf supply store as he is walking out of the police station after failing to convince the officers that there is strange activity going on at Third Street School and follows him. Prickly doesn't believe him, but his friends convince him to go with T.J. to the school. Unbeknowst to him, his former best friend, Phillium Benedict has taken over the school to use as a hideout and sabotaged the locks; the moment he puts his key in the lock, he is electrocuted and seemingly dematerialized before T.J.'s eyes. It is this incident that leads T.J. to enlist his friends' help, and he forces his sister Becky to pick up each of them. In actuality, the locks acted as a transporter, which was then used to outright imprison Prickly within the school. While Prickly is held prisoner inside, Kojak poses as him to avoid drawing suspicion (which consequentally causes T.J.'s friends to think T.J. lied to them, and after witnessing a device emerge from the school, suspect that Prickly is involved). The following day, T.J. finds Prickly's golf pants, which were taken from him and thrown in the dumpster, while hiding from the guards. T.J., around the same time, also finds Prickly talking with some of the guards, although he then learns that "Prickly" is in fact Kojak. That evening, when T.J. and his friends meet up again, they find a note in the pocket that reads "Help Me!", confirming that Prickly is being held prisoner, leading them to go inside to rescue him.
Unfortunately, they get caught, and while Gretchen, Vince, Spinelli, Gus, and Mikey are able to escape, T.J. is captured and thrown in the storage room, where he finds Prickly bound and gagged. Phillium Benedict then enters the room and courteously greets his old friend, though Prickly isn't too happy to see him. Afterwards, Prickly recounts how Phillium tried to get rid of recess, much to the chagrin of the parents, teachers, and students, prompting him to tell the superintendent, who stripped Benedict of his position as Principal and gave the position to Prickly, causing Benedict to turn on Prickly, especially when Muriel Finster dumped him out of disgust for his actions, as well as the President firing him from his post as Secretary of Education when he tried to get rid of recess on a nationwide scale.
The two then get to Prickly's office, which Phillium has reclaimed and messed up, where T.J. retrieves his baseball and the walkie-talkie Prickly confiscated from him prior to the summer. They also discover Benedict's true plan to get rid of summer vacation when they see graffiti saying "No Summer Vacation!" on the wall, to which T.J. alerts his friends. Phillium reveals to T.J. and Prickly that he plans to move the moon using a tractor beam when lunar perigee occurs, which will cause the entire planet to freeze over, then locks them in a cage. After an argument, Prickly tells T.J. about his childhood and how all kids eventually become grown-ups, then reveals that he took the keys while Phillium wasn't looking and unlocks the cage. They subdue two guards and steal their uniforms, and attempt to blend in with several other guards, who aren't fooled by their disguises, prompting them to flee and hide in the cafeteria, where they acquire a vat of corn chowder, which they dump on Kojak as he corners T.J.'s friends, who have rallied the rest of the students with Becky's help in an effort to reclaim the school.
While the students and teachers (brought in by Ms. Finster) fight against Benedict's guards, scientists, and ninjas, Prickly confronts Phillium as he prepares to activate the tractor beam himself, distracting him by telling him he has a spot on his tie, then punching him in the face, causing him to slump and trigger the beam, with the lever getting stuck, preventing Prickly from deactivating it. With no way to shut off the machine, T.J. throws his baseball to Vince and instructs him to aim it at the Photon Channeler, shattering it and causing the machine to collapse, foiling Benedict's scheme, leading to his arrest. In the aftermath of the battle, Prickly returns to his office to fix it up again, finding the peace symbol necklace from thirty years ago in his desk, when T.J. drops in on him to say thanks for all that he has done. Prickly, in turn, thanks T.J. for getting him involved, because it helped him remember why he started teaching in the first place, because he wanted to help children. T.J.'s friends then appear at the window, to which Prickly encourages him to go have fun with them, calling him "Teej"; T.J., in turn, addresses him as "Pete". As T.J. leaves with his friends, Prickly puts the necklace on, then reminds T.J. that when September comes, he's still going to be in big trouble for his "saggy butt" comment. T.J. tells him that September is a long way off, then runs off with his friends as Prickly sits in his window and watches them with a smile.
- As seen in Recess: School's Out, he was once part of the 60's counterculture movement and seemed to have a sunnier disposition, much like how Ms. Finster was hinted to have a similar attitude in the past.
- Also, in the film, it was revealed that he had round-frame glasses and brown hair, as opposed to his glasses and black hair seen in the series.
- The film also reveals that he has a brother named Thurgood who lives in Alaska.
- The film also reveals that he suffers from stress-induced stomach ulcers (presumably caused by his constantly having to deal with T.J.'s troublemaking nature), as he was seen putting alcacelcer tablets into his glass of water before attempting to read TJ the riot act for his posing as Prickly via a voice changer machine.
- According to both T.J. and Prickly during the above, Prickly once ended up getting arrested by the FBI due to misinformation about being a Chinese spy thanks to T.J. feeding them false information, with T.J. claiming he did it because Prickly gave an auditorium speech about personal hygiene.
- Coincidentally, Peter and his brother Paul Prickly share the same first names as two key founders of the Catholic Church, St. Peter and St. Paul.