The Son of the Slime Who Ate Cleveland by Marjorie Weinman Sharmat, 1985.

Frank is the first to admit that he’s a bit eccentric and that his mind doesn’t quite work like other kids’. He’s a bit more imaginative, more daring. When he thinks of something, he can’t resist doing it, even pulling pranks on his best friends, Jack and Lee. He sees it as a way of expressing himself, and he wants to go into show business someday.

One day, the boys spot a jelly bean counting contest at the mall. The prize is two tickets to a move called Monster Mayhem and all the jelly beans they can eat in two hours. Frank isn’t really interested in counting contests. Jack and Lee, who have ambitions to go into law and banking, are more interested in counting things and competing with each other. Jack and Lee both come up with the exact same number of jelly beans that they think are in the jar, and they start arguing about which of them came up with the estimate first. Frank can’t decide which of them was first, so he just tells them that they’re both wrong and guesses his own random number without even trying to count the jelly beans. All three of them enter the contest.

That could have been the end of it, but Frank can’t resist telling other people about the contest. Not only does he tell them that he and his friends have entered the contest, but he tells them the exact number that Jack and Lee both guessed.

A classmate, Bianca, invites everyone to a party at her house where everyone has to come dressed as their favorite monster. Her parents are also there, dressed as Mr. and Mrs. Slime Who Ate Cleveland. Bianca’s parents are both psychologists, and they think it’s emotionally healthy for kids to expend their energies and go wild at parties, so they’re very permissive with Bianca and her friends. At the party, Bianca’s father takes an interest in Frank, calling him “son” (hence the name of the book) and telling him that he should mingle more with the other kids and be less of a loner. He offers to help Frank with vocational counseling for his future, which Frank is not eager to accept from a guy who is currently dressed as a Slime Who Ate Cleveland and who actively encourages the kids to have a potato sack race in the living room. Frank thinks an indoor potato sack race sounds crazy, Jack thinks it sounds dumb, but Lee is all for it. When Jack and Lee argue about the potato sack race, Bianca brings up the story that Frank told her earlier about the jelly bean counting contest and the boys’ argument over which of them guessed the answer first, putting it to a vote among the party guests. Lee wins the vote (which doesn’t mean much since the other party guests weren’t even there when they made their guesses), and Bianca switches her attentions from her current crush, Jack, to Lee (who doesn’t want Bianca’s attentions and becomes afraid to answer the phone when she keeps calling him).

Jack and Lee both get irritated with Frank for turning the jelly bean counting contest into a big deal and ask him to stop telling people about it because neither of them really even expects to win. However, the incident doesn’t even stop there, because it turns out that both Jack and Lee are declared the winners of the contest because their identical guesses are the closest to the real answer. The contest judges decide to award the prize jointly to the two of them – a movie ticket each and all the jelly beans that each of them could eat in an hour.

Sharing the prize could have resolved the incident, but Jack and Lee still have a competitive streak. Even though Frank congratulates them both as winners, Jack and Lee still argue about which of them is the “real” winner for coming up with the answer first. Frank tries to point out that each of them really only needs one movie ticket anyway, so what difference does it make if the other friend gets the other one? That doesn’t do any good, though. Jack and Lee both want to be acknowledged as the “real” winner, and thanks to the vote at Bianca’s party, other kids at school are taking sides to support their votes.

The entire jelly bean counting situation has gotten completely out of control! Jack and Lee won’t stop arguing with each other about who really won the contest, and both of them are mad at Frank for spreading the word about it and turning it into a bigger deal than it had to be. Frank needs to find a way to solve the argument and reconcile with his two best friends. Meanwhile, Bianca’s father, Mr. Wasserman, keeps calling Frank “son” and trying to talk to him about his vocational future, which makes Frank feel as green as the Son of the Slime Who Ate Cleveland.

Just when Frank thinks he’s got everything solved, a new contest threatens to set Jack and Lee against each other again. Frank tries one more outlandish scheme that exposes Jack and Lee’s arguments to an even wider audience than before. It takes some sincere friendship from Bianca, some words that actually make sense from her mother, and some “perfectly frank” talk from Jack and Lee to help Frank to recognize how his own behavior has contributed to the problems and how his friends really feel about some of the things he’s said and done.

The book is humorous, but Frank does develop some empathy through the course of the story, coming to a better understanding of how the people in his life really think and feel and the effects that his various pranks and stunts have had on people around him. Frank learns not just what it means to be “Perfectly Frank”, as he puts it, but what it really takes to be a sincere and honest friend. One of the best parts of the book is the banter between the various eccentric characters, from Frank’s straight-forward responses to the strange offers of advice from Bianca’s well-meaning slime monster father to the school principal’s attempts to convince Frank to take up paper clip collecting as a hobby to keep him out of trouble to the frank discussion of friendship Frank and Bianca have when Bianca asks Frank to kiss her.

The book is available to borrow and read online through Internet Archive.