The kids are really looking forward to their field trip to the aquarium - especially when they remember the scary Lock Jaw from their last trip. But, when they get there, they see that Lock Jaw isn't really that scary. Arnold notices how neglected the old turtle looks, and returns later with Grandma to set it free.

Arnold's hat lands on the stoop of "Stoop Kid," - a bully who has lived his whole life on his stoop, and is highly protective of it. But, when it's Arnold's fault that Stoop Kid becomes the joke of the city, he must help Stoop Kid face his biggest fear - leaving his stoop for the first time.

Helga is annoyed when Rhonda doesn't invite her to her slumber party - everybody assumes that "girly" parties aren't Helga's style. So, Helga is determined to prove her wrong, and gets a makeover.

Arnold has a really bad day - the city is suffering from a heatwave, and whatever he does, Arnold just can't seem to get cool.

At the Annual Cheese Fair, Helga tries her best to keep Arnold well away from Ruth - a girl who Arnold has a crush on.

Arnold and friends decide to clear out a vacant lot to play baseball on, but the adults take over it, and use it for their own reasons.

Arnold attempts to do something that no other kid has done before - completing the entire list of a kid's perfect Saturday! But, unfortunately, things don't go quite to plan.

When the kids complain of being bored, Grandpa tells the story of the Haunted Train. So, the kids decide to go and see if the train exists for themselves.

An older cool guy befriends Arnold, but Arnold realizes that he is really a shoplifter.

Arnold and the gang set out on a quest to find the hidden treasure of the mysterious "Wheezin' Ed" on Elk Island.

Arnold is given the assignment to tutor Torvald, the meanest, toughest kid in Arnold's math class, for the big math test on Friday.

When Arnold's pigeon gets sick, he takes it to "Pigeon Man", a person surrounded by pigeons who lives in a rooftop.

Eugene is accused of pulling the fire alarm. In the school court, the jury thinks Eugene is guilty except for Arnold, who believes there is a shadow of a doubt.

The kids try to get in the book of world records so much that they would do anything, including most people on a one-person bike and the longest game of Crack-The-Whip.

Arnold has a magic show and he makes a disappearing act and uses Helga as the person disappearing. Helga decides to play a trick and literally disappears. She bumps into a pole and has a dream on how the world would have been if she's gone.

Arnold and the gang must stop Big Bob from chopping down the oldest tree in town.

Gerald's secret is revealed; he doesn't know how to ride a bike, so Arnold teaches him how.

Arnold and Gerald compete against Helga for the school newspaper.

When Harold is walking in the street, he finds a kitty that belongs to an old lady and he takes it, but then everybody appears, and Harold has to surrender the kitty to the old lady.

Schoolyard tradition has it that on the first Monday of June each year, the fifth graders throw the fourth graders into trash cans. So, Arnold and Gerald try to make a run for it. As more people are thrown into trash cans and the fifth graders know all the routes, Arnold and Gerald find out eluding the fifth graders is harder that they thought.

Arnold and Gerald do a spot of fishing, determined to catch the pond's biggest fish, the legendary "Big Caesar".

After Arnold saves Sid from an injury, Sid devotes himself to paying Arnold back with unending kindness.

Wolfgang and his gang of fifth graders challenge Arnold and his friends to a football game, but he has to first persuade them that his plays are good enough for them to win.

Phoebe becomes hall monitor and asks Helga for tips. She becomes overwhelmed by the "power" and soon everyone wants the old Phoebe back, even Helga once she realizes Phoebe's also giving her detentions.

Helga and Arnold fall asleep and have their own "parody/dream" of the opera Carmen.

Arnold and a descendant of his grandpa's arch enemy, Rex Smythe-Higgins, compete in a boat race.

After creating an idea for a parade float, Arnold is confident of it showing up in a parade.

Sid pretends that Arnold's room is his, since he's ashamed of showing his real room to Lorenzo.

Stinky's simple life changes after he becomes the surprise new spokesman for Ya-Hoo Soda.

Curly gets enraged after a minor playground mix up. He locks himself in the principal's office and refuses to come out.

Principal Wartz gives Sid a detention believeing he placed fake vomit so he could trip over, even though it wasn't Sid who put it there. As a result, Sid seeks revenge and reates ""Revenge Doll"" of Wartz's face, like they do in tribes. He thinks he killed Wartz with the curse. Arnold thinks he's paranoid, even though there are a few clues hinting out that Wartz is dead.

A roller coaster breaks down while Eugene and Arnold are at the top of its tallest drop.

Arnold finds out Iggy wears bunny pajamas with feet in them, and Arnold accidentially spills the beans to Sid and Stinky, ruining Iggy's cool image.

The Coach wants to remarry Tish and asks Arnold to be his best man. Along the way, Arnold teaches the coach a thing or two about love and sacrifice.

Rhonda holds a cool-people-only party at her house. In retaliation, Arnold and his friends hold a "geek" party on the roof of his boarding house further up the street, leaving Rhonda's party deserted.

Helga, lost in a love reverie, writes 'Arnold loves Helga' on a wall, but changes the name to 'Lila' when the kids approach. Lila thinks that Arnold loves her until he explains the mistake. Then he falls for Lila and she is forced to break up with him.

The kids compete in a grand prix race against each other.

Helga tells jokes about her classmates, who take offense to it.

The town is flooded and Arnold's class is trapped in the school.

Arnold, Grandpa, and friends reenact the Pig War.

Arnold is okay with working with Gerald at Mrs. Vitello's flower shop after she's injured and puts Gerald in charge, but not with working for Gerald, which causes the friendship to hit a snag and Arnold quits.

Lorenzo, a neurotic rich kid, comes to P.S. 118. All the kids try to help him become an average kid.

Harold, Sid, and Stinky all moon Principal Wartz, but Arnold is blamed, even though he was just an innocent bystander.

After Sid works off a debt with loan shark Big Gino, the two become friends, but when Sid is told to give Arnold a swirlie, he has to choose between the two.

After losing Eugene's birthday party invitations, Arnold feels obliged to throw him another party, but it doesn't work out.