The target of the Great Brain's final scheme, Andy is also the reason for the Great Brain's ultimate reformation. Over the summer, Andy gets gangrene in his foot from stepping on a rusty nail in the barn the kids aren't supposed to play in, and Dr. LeRoy amputates his left leg below the knee:
At first all of us kids were quite awed by the peg leg. We tried it on and walked on it. But the novelty soon wore off and we began calling him Peg Leg. Andy couldn't join in most of the games we played. His father must have realized this and had ordered an erector set from Sears Roebuck. I guess he thought the erector set would draw kids to the Anderson home where they would play with Andy. He was right. (8.2)
Tom decides he needs that erector set so he can charge kids to play with it, so once he realizes Andy is so depressed he wants to die, Tom offers to teach him how to do everything he used to do with two legs—in exchange for the erector set. Tom succeeds, and Andy's transformation teaches him that sometimes doing good makes you feel good, and feeling good is its own reward. For more on this, swing by the Great Brain's page in "Characters."
The boys almost immediately start calling the new kid from Greece Basil, so that's what we'll call him here, too. Tom takes it upon himself to turn Basil into an American kid who gets respect from the other boys. Of course, what Tom gets out of this is the money Basil's dad hands over in exchange for all his hard work:
He had an olive complexion and black curly hair. He was wearing a funny hat with a feather in it. He had on green britches with green suspenders and a shirt with a lace collar on it. Nobody but a genuine immigrant boy would have dared to wear an outfit like that in Adenville. He reminded me of a valentine. (5.2)
Since cultural sensitivity is not exactly this community's strong point, we can bet dollars to donuts this kid is going to get beaten up. And that's exactly what happens, until Tom turns his great brain to the problem of showing the other kids that Basil is not to be messed with. Well, except by him.
Now that Tom had made Basil a genuine American kid like the rest of us, it made the Greek boy fair game for my brother's great brain. Right now, I thought to myself, I'll bet Tom is trying to figure out how much to charge Mr. Kokovinis for each new English word he teaches Basil. (5.213)
Good luck, Basil.
Frank and Allan are involved in two of the Great Brain's schemes. First, they are the brothers who get lost in Skeleton Cave with their dog, Lady, and are rescued through Tom's plan. Tom's plan isn't totally selfless, though, because he's already planned to mate Lady with Brownie and set up a series of conditions that guarantees he'll make two silver dollars on the pups. To tell the truth, Frank and Allan don't seem terribly bright if they're dumb enough to explore a cave known for having skeletons of people who already died there in it. Luckily, Tom's rescue plan saves them and his plan for the puppies makes them a silver dollar apiece.
Every group of kids needs at least one bully, and Sammy Leeds is "sort of a bully with kids younger and smaller than him" (5.4). Though he's never actually the target of one of Tom's schemes, he is the guy to beat up when Tom is teaching other kids to beat someone up.
Because his father hates immigrants for taking American jobs, Sammy immediately starts picking on Basil, prompting Mr. Kokovinis to promise Tom a dollar to teach Basil to beat up Sammy. Then, when Andy Anderson needs to win a wrestling match in order to earn back his self-respect, Sammy is the champ to beat. He's not a thoroughly bad kid, but he has learned prejudice from his father and gets his own sense of self-worth from knocking others down.
Howard Kay is J.D.'s closest friend in the group because he is closest to J.D. in age. He's such a good friend that he's willing to infect J.D. with the mumps so J.D. can finally get one over on his big brothers by getting an illness first. J.D.'s not always the brightest light, and his one attempt to scheme like the Great Brain proves it.
In this group, Tom and Sammy are leaders and Jimmie is a follower. He doesn't care whom he follows, either, so long as they seem to have a plan. And no, it doesn't matter what the plan is: He goes along with Sammy when Sammy bullies Basil, and he goes along with Tom when Tom decides to convince the school board that Mr. Standish is a secret drinker. Because his mother runs the boarding house, Jimmie plays the key role of actually planting the evidence on Mr. Standish.
As two of the poorer kids in town, Pete and Seth are easily persuaded to pay Tom a penny each for the chance to lick the ice cream spoon at the Fitzgerald house.
Just two more kids in the kid group. We don't get much beyond their names.