Jocktopus plays in the football team with Pass, Punt and Fumble. His girlfriend is Piranhica, a piranha from school. He thinks learning is "boring". People usually avoid him, due to him being the most aggressive and strongest. Apparently, he minorly likes helping around the house with chores according to his fishbook profile.
When Milo and Oscar sneaked to the girls, the girls sang, and Milo and Oscar kicked Jocktopus and he got real mad. So Jocktopus strangled them for kicking him ("Fish Sleepover Party"). When Mr. Baldwin does attendance, Jocktopus responded by saying "JOCKTOPUS!" ("Fish Out of Water"). Jocktopus was the MVP and was widely popular for his football skills. He even signed everyone's faces. When Milo tried out for the tryouts, Jocktopus complained and yelled that that is not football. Jocktopus was angry Coach Salmons saw agility and moves on Milo. When the game started, Jocktopus was suffering for water, since the Gecko tank is very hot. Later, when Milo came, he sprayed everyone and Jocktopus made the last score of the game. Jocktopus said he had one thing to say to Milo when they won the game. It was "Jocktopus", and he cheered Milo like everyone else ("Underwater Boy").
Jocktopus had a major role when his birthday was up, and Milo, Oscar, and Bea needed to give him something. They decide to give him money. When Sunny gave him all his money for his birthday, he thinks money is "worthless paper" and he puts Sunny inside a "punch later" box. When they found out Jocktopus hated money, they gave him Oscar. Jocktopus brang Oscar to his locker. He later found out that Oscar was smart, so Oscar helped him with his bullying to avoid getting punched. When the program chose Albert Glass, Jocktopus used the dice and notecard. Albert thought it was beautiful, but Jocktopus just beat him up. Mr. Baldwin spotted him and Jocktopus told Oscar what happened. Oscar stayed with Jocktopus and refused to go back to Milo and Bea. But the program chose them, so to protect his friends, Oscar saved them by making Jocktopus punch himself and he told his girlfriend, Pirahnica to stay out of this ("Happy Birthfish, Jocktopus").
When the test was coming, Jocktopus groaned ("Fail Fish"). When Milo told Oscar to laugh at everything, Oscar accidentally laughed at Jocktopus when he tripped. Jocktopus grabbed him and told him to meet at 3:00 so he can pummel him. Milo came with a plan to laugh at Jocktopus, so Oscar got wrapped in Jocktopus' arms and he starts laughing crazily. Jocktopus says he is freaking him out. Then, everyone in the school started laughing at Jocktopus. He then swims away, crying ("Funny Fish"). When Oscar needed a new roommate, Jocktopus said he needed a new roommate cause he broke his other one, making Oscar immediately say "NEXT!" ("Dances with Wolf Fish"). Jocktopus' counterpart in Freshwater Castle was "Joustapus". He tried to charge at Oscar, but he failed when the point of Oscar's sword paralyzed him ("The Tale of Sir Oscar Fish").
Jocktopus was once beating up Albert and he made fun of him. Milo, Oscar, and Bea felt bad for him so Milo taps Jocktopus in the back and telling him it is not cool doing this. But Jocktopus punches Milo out of the tank. Everyone gathered around seeing Jocktopus putting Albert to a light bulb. Then Milo comes with his ninja and the ninja overpowers Jocktopus. Jocktopus eventually got in a glass bowl for having bad behavior. When Oscar later mentioned that Milo is worse than Jocktopus, Jocktopus agrees, saying he was never this bad as Milo ("Milo Gets a Ninja"). When Albert had the dropsy, Jocktopus got balloons with Albert faces drawn on them and promises to not punch Albert and punch balloons instead ("Dropsy!"). When Milo became big and strong, Jocktopus and the other students watched him smash through Mr. Baldwin's classroom wall. After Milo became too strong and went to Freshwater High, Jocktopus and Piranhica were holding hands and screamed when they saw Milo ("Big Fish").
When Milo asked the boys what the most radicalistic thing they know, Jocktopus said "JOCKTOPUS!" When Clamantha disguised as a boy to spy on the boys, she got spotted by Jocktopus, who picked her up and threw her out of the window. When the boys and girls battled in each of their float, Jocktopus was fighting with the boys. He tried to dodge all the pearl Clamantha spat on the boys float, but got hit by one of them. At the end of the episode, Jocktopus and Piranhica became the homecoming King and Queen, and they both kissed on top of the float ("Fish Floaters").
Pirahnica is head over fins in love with Jocktopus, and they are seen together lots of times (Queen Bea, Happy Birthfish, Jocktopus, Big Fish, Two Clams in Love). Pirahnica calls him names like "Babe" and "Big Dreamy Hunk". When she did, Jocktopus told her to stay out of this, which means he does not like it when she sweet talks him in public. The two were crowned King and Queen of homecoming and were kissing on top the float ("Fish Floaters").
Jocktopus interacts with Oscar way more than Milo and Bea. Oscar is of course terrified of him, and Jocktopus likes beating him up. Oscar is not Jocktopus' "friend", but he said once though. But Oscar later regrets it when he calls him his friend, but Jocktopus says he is not his friend and that he owns him ("Happy Birthfish, Jocktopus"). They meet again when Oscar laughs at him because of Milo's plan to get out the fight. After Jocktopus is embarrassed by the room of students laughing at him and runs off.
- His name is divided from "jock" and "octopus".
- He has a big room inside a tiny locker, where he practices his punching ("Happy Birthfish, Jocktopus").
- He's the quarterback in his football team ("Underwater Boy").
- Milo and Oscar actually called Jocktopus "cute", in which Jocktopus responded by throwing them ("Fish Sleepover Party").
- The line Jocktopus uses when bullying is "Daah! Jocktopus is hitting you now!" ("Happy Birthfish, Jocktopus").
- Jocktopus' eighth arm is his favorite out of his other arms ("Milo Gets a Ninja").
- His full name is "Jocktopus Ludwig Vandenbush" ("Happy Birthfish, Jocktopus").