When Buster defeats the Brain in a math contest, he is chosen for the school mathathon. Crushed, the Brain says he's decided to become a comedian and declares Buster the new "brain."

When Buster impulsively drops a Cybertoy into Arthur's backpack in the drugstore one day, he feels so guilty that he finally confesses to his friend and they try to return the popular toy before anyone else finds out.

Fern dares Arthur and his friends to enter the poetry writing contest at the local library, but writing poems turns out to be harder than they thought.

When Buster rescues a cat stuck in a tree he is treated like a hero, but when he begins to enjoy his celebrity a little too much, his friends devise a plan to bring him back to his old self.

Brain and Francine devise the perfect plan to get even with Muffy after she bribes the judges at the science fair.

When Arthur hears his sister singing a catchy tune, he wonders if he could call that jingle his own and enter it in the Crunch Cereal Contest.

Buster tries to convince Arthur, the Brain, and his other friends that he not only saw a UFO but also a comet heading for the earth.

At Prunella's half-birthday party, her sister unveils a fortune-telling cootie catcher that seems to be able to predict the future.

When Arthur gets the hiccups, his family and friends try everything they can think of to make them go away.

When Arthur's third-grade class goes hunting for fossils at Rainbow Rock State Park, his friend Buster actually finds one, and instead of turning it in Buster decides to take it home--but he soon regrets his decision.