Sid thinks Stinky is a vampire.

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

Gerald is involved with his new favorite game which Arnold dislikes.

Arnold, Gerald, Harold, Sid and Eugene go on a fishing trip with their fathers and Phil.

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.

Arnold gets stuck in a tree with Harold and Eugene.

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

Helga inscribes her name in her Arnold locket.

Sid becomes obsessed with cleanliness.

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.

Gerald's Ghost Bride story inspires the other boys to venture into the cemetery at night, but they may have bit off more than they could chew, because they're hunted down by two different Ghost Brides.

Gerald gets jealous because he thinks Jamie O. is trying to steal the girl he likes, when, actually, the girl likes Jamie O.

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 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.

Mr. Hyunh, Oskar, and Ernie purchase a race horse, or so they think.

Curly gets Rhonda to act like his girlfriend after something happens to Rhonda's mother's fur coat and he fixes it.

Stinky, Harold, and Sid are on the run after they think they blew up a police station.

Mr. Hyunh has Arnold pretending to be his son for his new employer.

Grandpa's Packard is stolen from an antique car show.

Phoebe gets embarrassed after she "passes gas" in front of a microphone.

After Mr. Simmons wins an award, a TV station does a documentary on how he teaches.

After Big Bob has a heart attack, he tries to become nicer.

Rhonda uses a folding paper fortune teller to see who will marry who, and Arnold and Helga get paired up, causing them to both dream what life would be like married to each other.

Arnold does something for Timberly, causing Timberly to have a crush on Arnold. She makes Lila start to like Arnold because he has been helping Timberly.

Eugene gets the lead role in the school musical "Eugene, Eugene". But the play director cuts the parts that Eugene is a hero, and makes the parts look like he is a loser.

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.

Arnold finds a journal describing the adventures of his parents in the Jungle. Also, it contains a map telling where they had to go after they left him.

Arnold finds a journal describing the adventures of his parents in the Jungle. Also, it contains a map telling where they had to go after they left him.