Principal Stickler was a nice principal at Freshwater High, but can get strict and dramatic sometmes.
Principal Stickler presented Oscar with the most popular student award when Oscar tried to be funny ("Funny Fish"). He makes Nurse Fishington do lots of stuff like pushing his chair and various other things. When Oscar tried to find a new roommate, Principal Stickler had his biggest part when he was shown to be a clean freak like Oscar. He and Oscar were doing great at first, but their friendship later got messed up when Oscar and Principal Stickler watched TV and Principal Stickler thought the fly in the show was real and evil, so he told Oscar to throw him. He did, but he ended up smashing the TV. When Principal Stickler vacuumed, he started vacuuming Oscar's braces and his eyes. When Milo came, the wolf fish started to attack Principal Stickler instead, so he used his vacuum against them ("Dances with Wolf Fish"). When Albert had a case of the "Dropsy", which is an illness for fish, Principal Stickler told Nurse Fishington to put Albert in a bag and send him to the clinic. Principal Stickler told everyone to wash their hands to avoid any contamination. When Milo saw how much treatment Albert was getting, Milo pretended to have dropsy, so Principal Stickler put Milo next to Albert, thinking that Milo really had dropsy. Later, when Albert got cured, Milo said he was still sick so that he could stay, so Stickler sent Milo to the dropsy colony, which had other sick fish with dropsy ("Dropsy!").
When Milo turned giant after staying in the "Big Tank" too long, he went to Freshwater, only for the students to mistake him as a "Navy Boy Monster". Principal Stickler thought he was trying to wreck his school, so he got out his secret army. When Bea told Stickler that the "Navy Boy Monster" was actually Milo, Stickler told the secret army to go back into hiding ("Big Fish"). Principal Stickler came into the classroom and told Mr. Baldwin that he had an announcement one day. Stickler told the class that the Homecoming parade was coming and he would need a grand float for the parade. The girls and boys suggested him different ideas, so Principal Stickler decided to make a friendly competition for girls against boys. After the competition ended, Stickler came into the field, asking why there were so many explosions in there. He stopped to see that the two floats had crashed together to make a Principal Stickler float, so he asked which team had made the float. Since both of the teams had "created" it, Principal Stickler said that everyone won ("Fish Floaters").
When Milo, who believed that Fish Brain Parasites were real, ran away from Albert, he ran to Principal Stickler's office. Milo told Stickler that Fish Brain Parasites were taking over the school. Stickler, unlike others, believed Milo's theory, and told Milo that not only were the parasites taking over people's minds, but they were also starting to steal his stuff. Principal Stickler told Milo that the only way to get rid of the parasites was to drain all the water from the tanks. He and Milo then went to his secret office, and pressed the button that made all of the water wash out from the tank. Principal Stickler gave the water back to the tanks after he and Milo thought the parasites were dead ("Parasite Fright"). When Milo told everyone that he was having a "Cinco De Milo" party, which was only a scam to lure everyone out of the tanks, Principal Stickler announced that there was an awesome party in progress. Stickler, along with the rest of the students, left the school to go to the party ("Pamela Hamster Returns"). When Bud was cleaning the tanks, Principal Stickler told everyone to evacuate the tank. Bud swept up Stickler, which caused him to fall on Mr. Baldwin, having one of his spines stuck in his head ("Diary of a Lost Fish").
When Principal Stickler came into the room one day, he said there was a lobster attack, which made Mr. Baldwin panic. However, Principal Stickler was just kidding. He then annoucned that there was a special student who won the perfect attendance award. He said the winner was the "tall sweaty one", who was Oscar. Principal Stickler told Oscar to receive the award and take a picture with the mayor. After Oscar said that this was the happiest Wednesday of his life, Principal Stickler realized it wasn't Thursday, so he told Oscar that he would win the perfect attendance award the next day. After Oscar came to school on time, Principal Stickler came and congratulated Oscar for winning the award ("Run, Oscar, Run").
He had a rather large role in "Principal Bea", his last speaking appearance. In the episode, it is later found out that Nurse Fishington put Principal Stickler into a filing cabinet after she tripped on his banana peel and fell on one of his spines. The spine got stuck in Nurse Fishington and caused her to become a dictator to the school, controlling Bea so that everyone would think it was Bea ruining the school instead of her. When Milo, Oscar, and Bea found Principal Stickler in the principal's office, he led them to his secret lair under the office. Nurse Fishington, however, got there first, and tried to destroy them. Bea sent Milo and Oscar to try and fight Nurse Fishington while she and Principal Stickler tried to fix Nurse Fishington with a computer. After being chased by Nurse Fishington for her bowtie, Bea noticed that one of Principal Stickler's spines was stuck in her. She, Milo, and Oscar then held her down while Bea removed the spine. After Nurse Fishington went back to normal, Principal Stickler made her the new principal, and decided to use a giant robot he had to leave the school and pet shop altogether. It is not known if he left forever, as he was seen again in "The Big Woo".
She is his assistant whom without, he can not move around quickly. She also cleans whatever he tells her to and is the butt of many of his jokes. Stickler built her to do his job ("Principal Bea").
Principal Stickler seems to deem Oscar as trustworthy and a good student, to the point where he was okay with moving in with him. He also presented him with the most popular student award when Oscar's fake laughing made the entire school happy.
He doesn't really care for Bea much and called her "the fake red head" once, much to her annoyance. ("Fish Floaters").
Although it's not shown, it's possible that Stickler does hold a resentment to Milo, due to his crazy plans and mischief. He once called him "the child that looks like a dinosaur". Milo calls him "Principal Stickies".
- He fools people by breaking and regenerating his spines ("Dances with Wolf Fish").
- He is able to move 2 of his spines like arms.
- He was principal in "Get a Yob!", but the episode "Principal Bea" was produced after "Get a Yob!". That means Nurse Fishington is still the principal of Freshwater High.
- His mother was a lunchlady at Freshwater High ("Get a Yob!")
- In human form, Principal Stickler resembles Danny Douglas from Future-Worm.
- "Funny Fish" (First appearance)
- "Dances with Wolf Fish"
- "The Tale of Sir Oscar Fish"
- "Milo Gets a Ninja" (Non-speaking cameo)
- "Big Fish"
- "Fish Floaters"
- "Parasite Fright"
- "Pamela Hamster Returns"
- "Diary of a Lost Fish"
- "Good Morning, Freshwater"
- "Run, Oscar, Run"
- "Fish School Musical"
- "Halloween Haul" (Non-speaking cameo)
- "Fish Talent Show" (Non-speaking cameo)
- "Break Up, Shake Down" (Voice only)
- "Get a Yob!"
- "Principal Bea"
- "Pool Party Panic" (Non-speaking cameo)
- "The Big Woo" (Non-speaking cameo)