When Arnold gives the superhero Monkeyman a taste of normal life, he's far too busy to bother helping the weak and downtrodden.

Helga and Harold must return to town on their own after the bus leaves them behind after a school trip to a chocolate factory, and Helga has tickets for a wrestling match and she can't be late.

Helga decides to act like Lila so Arnold will like her..

Mr. Green runs for city council.

Sid thinks Stinky is a vampire.

Olga gets into a "Big Sis" program, but her "Lil' Sis" is Lila.

Arnold, Sid and Gerald find a bag filled with money, but when Arnold loses it, everyone thinks he stole it.

When Mr. Simmons is upset that Principal Wartz is being too strict with the students, Wartz decides to resign and he selects Mr. Simmons to take his place. The newly promoted Principal Simmons decides to make massive reforms to permit the school environment to be more liberal, though will the students at P.S. 118 appreciate his authority?

The kids must face two bullies when a new kid, Ludwig, returns and wants the vacant lot for himself.

When Phoebe breaks a leg after being hit by a truck, Helga believes it's her fault (and it is), so she starts being nice to Phoebe. Yet when Phoebe's leg heals, she decides to stay disabled for a little longer.

Helga inscribes her name in her Arnold locket.

Sid becomes obsessed with cleanliness.

Harold is suspended and will do anything to get back into school.

Ernie starts dating a tall model, but she doesn't want to continue dating him because of his height.

Arnold asks Grandpa what really happened with his parents, and he finds out that they disappeared after they left the country on a plane, although they might still be alive.

When Arnold, the boarders and the Patakis go to the beach, a girl uses Arnold to win a sandcastle competition. Ernie gets buried in the sand. Miriam and Suzie start taking dancing lessons. Grandpa thinks he's stuck on an island. Oscar starts using a metal detector to find ""treasure."" Big Bob gets a bad sunburn. Helga tries to warn Arnold that he's just being used.

Arnold gets stuck in a tree with Harold and Eugene.

Rhonda's family goes broke and they move into the boarding house.

Helga gets amnesia, and Arnold starts acting nice to her.

Grandpa Phil and his old friend have been feuding for quite some time, as their friendship fell apart years ago. However, they still attempt to compete with one another as they each believe they are the better individual; though when both men decide to enter the extremely dangerous Old Iron Man triathlon, Arnold attempts to put an end to their feud, as he does not believe they should risk their lives over something so trivial.

Arnold visits his cousin Arnie, whose friends look remarkably familiar to Anrold's

Chocolate Boy wants to give up chocolate.

P.S. 118 is having an Arm Wrestling contest, but Harold get humiliated when he loses to Patty before the contest, so he asks Patty for some pointers on winning.

After Arnold saves the life of a rich man, the man invites Arnold and Grandpa Phil to his house. He tells Arnold that he wishes Arnold was the son he never had, but he really does have a son, but they share nothing in common.

Arnold is sick and tired of everybody preforming their April Fool jokes on him (escpecially Helga), so he tries one of his own, but it backfires when it temporarily blinds Helga.