Binky Barnes- Although he was originally a bully, he later became one of Arthur's friends. He is still in third grade due to being held back. Oddly enough, he likes butterflies and he takes ballet. Binky is shown to be more sensitive than the other members. Though he is now his friend, he is still a bit of a bully and enjoys maintaining his strong personality.
Molly MacDonald - Molly is a member of The Tough Customers. She is a huge tomboy. She listens to heavy metal, like one band named Mutacrude - a parody of Motorhead. Like Binky, she also shows a sensitive side, like she is very protective of her little brother James and occasionally hangs out with the third graders. She becomes friends with Arthur in Season 11. She enjoys making fun of Arthur's friends, especially Muffy, whom she calls "money bags". Her and her brother are of Scottish descent. The reason she became a bully is because some older kids made fun of her hairdo when she was in preschool. Arthur's sister DW has a crush on her brother.
Rattles Ciccone- A member who seems to be one of the toughest and meanest of the Tough Customers. He also has a sensitive side, but very rarely shows it, though he cares for a giant dog. It is likely that he often takes the lead as the leader. He doesn't seem to be very smart due to the fact that he can't seem to be as good at bullying as Binky. He enjoys fighting with others. He also enjoys extreme sports, like when Binky told him that he was going to get hurt, Rattles calls him a squealer. He is a skateboarder of Italian descent.
Slink - A tall member and a rabbit. He was shown as a person that originally went to Mighty Mountain but now goes to Lakewood. He enjoys making fun of Arthur and Buster. His attitude is cocky and a bit ditzy. He is a skateboarder and is shown in the episode "Buster and the Daredevils", where he and Toby mock Buster and Arthur for still acting like kids. He has a sister named Nancy who sometimes hangs out with DW.
Toby - A skateboarder shown as the main antagonist in "Buster and the Daredevils". He seemed to have little personality outside of his bully attitude. He forced Buster to eat some kind of bug, but Buster fortunately stood up for himself. He was Slink's friend before Slink switched schools.
Keiper - A member who enjoys fighting and one of the strongest members. He is large and bulky and looks like a cat. He is no longer seen or mentioned as being a member.
In an episode in Season 6, the members all try to eradicate music. This plan was thought up by Binky in order to settle a score of his.