"The Meanest Thing to Say" is episode 6A of Little Bill.
The episode starts with Little Bill, Andrew, Fuchsia, and Kiku playing Pirates at school by walking around and wearing pirate hats. Fuchsia is the mean captain of the all, and Kiku is nice, but her parrot is mean, too. Little Bill has just found a treasure map, so that it can help them find the treasure to keep it for themselves. The kids all agree to that. Just then, Miss Murray tells her whole class that they need to pay attention for a few minutes. A new boy is standing next to her, and Fuchsia wonders who he is. Miss Murray tells everyone that this boy is joining their class, and introduces him as Michael Riley, who recently moved from Miami (Florida). Everyone says hello to him, but he feels a bit shy and doesn't say anything. Miss Murray then tells everyone that they'll be having extra play time in the yard today.
The kids all go outside. Fuchsia grabs the basketball and throws it to her cousin, who misses and goes to get it back. Michael grabs it for him, and he asks him if he plays to play basketball with them. Little Bill says that every time they shoot the ball, they have to say pirate things. Michael won't play that and knows a better one to play, Ranking, where you say mean things to one another. Kiku doesn't understand why they would be mean, but Michael tells the others that whoever says the meanest things wins. Little Bill thinks he's being mean, doesn't want to play that game, and wants to play basketball. He then shoots the ball, but he misses, and Michael starts to play Ranking, telling him that he shoots like a peanut head. It's Little Bill's turn to say a mean thing, but he doesn't know what to say, so Michael tells him that he's a poo-poo diaper baby, hurting his feelings. The bell then rings, and everyone goes back in. Andrew tells Little Bill that they need to go, and Michael tells him that they'll be playing again tomorrow, so he has to think of some very mean things to say. Michael heads back inside, and Little Bill sulks after him.
That night, Little Bill is in his room and trying to think of something mean to say to Michael. He says that he has a mushy head, but doesn't like that. Little Bill thinks of Michael as a banana and April walks past when he does, asking him what's he's doing. Little Bill is still thinking of mean things, but April tells him to think of something better than a banana. He asks how, and she says that if he acts mean, those things will sound mean. Little Bill asks if a pirate would work, but April tells him to come downstairs for dinner. Little Bill then imagines that he's a mean pirate on an island, and starts to stomp around, saying mean things. A mean parrot flies in, and he tells him that he's the meanest pirate ever.
Little Bill is snapped out by Brenda, who tells him that dinner is ready. He tells her that he's a mean pirate, walks down to the dinner table, and stomps in. Alice the Great tells him that tonight's dinner is macaroni and cheese (his favorite). Little Bill still pretends to be mean, and stomps to the table. Brenda asks why he's suddenly mean, and April tells her that he's trying to say mean things. Little Bill tells his family that he has to play Ranking tomorrow. Big Bill, saying that it was called Playing Dozens when he was a kid, and he won it every time that he played without saying one mean thing. Little Bill asks how, and his father says that none of the things that his friends said about him were true, and he only said, "So?" Little Bill is shocked that it's all his father ever said, and tells him that he was called a peanut head today. His father asks about that, but is told that it's false, so he tells Little Bill to just say, "So?" because it still isn't true. Little Bill also remembers that he was called a peanuthead and a poo-poo diaper baby, but also disagrees to that. Big Bill asks him if he cried, and Little Bill says that he didn't, so he tells him that to win, he only has to say, "So?" Little Bill realizes that he won't have to be mean, and is ready for tomorrow.
The next day, the other four kids are still playing Ranking. Michael tells Andrew that he has hair so red that he probably uses ketchup for shampoo, and it's now Andrew's turn. Little Bill arrives, says hello to everyone, and is told that he smells like old egg salad, but only says, "So?" Michael says that he's a goofball that looks like a slimy slug, but he replies again, "So?" Michael says that Little Bill is a teacher's pet with bugs on his head, but he says one more time, "So?" Little Bill smiles, and the others realize what's happening. Michael still has to be called such names as a creepy crawler or stinky cheese. The others start to laugh and tell him that stinky cheese is funny. Michael tells them that they need to be mean, and are supposed to get upset and cry, and he asks Little Bill and his friends why they're laughing. Little Bill says that that's funny, and starts to laugh with the others. This makes Michael so sad that he walks off. Kiku notes that Little Bill didn't have to be mean. Andrew asks him why he kept saying so, and is told that he didn't cry, that none of what Michael said was true. The rest of his friends understand that point.
The four kids decide to play Pirates, and run inside to do that. Little Bill sees that Michael is sad, and sitting alone. He says hello to him, and Michael apologizes for saying all of those mean things. Little Bill forgives him, and is amazed that his new friend isn't mad at him. Michael says that it wasn't true, is invited to play Pirates, agrees, and wants to be the funny one. The two then run over to play with the others, ending the episode.
There is sort of a reverse in this episode, as in the book of the episode's same title, Michael referred to the mean-name-calling game as "playing the dozens," while Big Bill said that in his childhood, they called it "ranking."
This is one of the first few episodes where Michael is mean to Little Bill, until he finally learns his lesson.