Jim has put up with Peter's monsterous alter-ego long enough, and seeks to cure him. However, the cure might turn Peter into a plain ol' dumb dog.

Evil Jim creates evil opposites of the Princess and Peter, which have some major flaws.

Bob, the Killer Goldfish creates an device that sucks the "evolutionary energy" out of anything that it wraps around. Jim and Peter are made into idiots by it, and remain idiots for a large percentage of the episode.

Psy-Crow is tired of Queen Slug-For-A-Butt giving him orders, and seizes the throne of Insectika. Since Psy-Crow is an even worse ruler, Princess What's-Her-Name, Jim, Peter and Mrs. Bleveredge, must stop Psy-Crow and put the queen back on her evil throne.

Evil the Cat and Malice the Dog work together to summon The Fiend Which Dares Not Speak Its Name.

The queen is mighty peeved at Psy-Crow for dethroning her in the last episode, and demands that he destroy Jim once and for all. After gaining superpowers from drinking too much espresso, Hyper Psy-Crow battles with Jim, resulting in the destruction of the universe.

Professor Monkey-For-A-Head is using a special peanut butter formula to turn everyone into a witless monkey. However, Jim is more concerned about how badly his show's ratings are slipping, and tries to get more people to watch through a technology called "Earthworm Interactive."

The League of Heroes declares Jim an unfit superhero, and forces Jim and Peter to switch their roles. Meanwhile, Evil the Cat is trying to destroy the Earth with the help of a cursed song and two dime-store lounge singers.

Professor Monkey-for-a-Head builds a doom machine for Queen Slug-for-a-Butt that transports Jim to an alternate universe. The alternate universe has several characters from the regular universe.