Molly MacDonald

 Molly MacDonald  is a fourth grader and an old member of the Tough Customers. Despite her tough exterior, she has also shown her more creative side in episodes like "The Agent of Change". Her younger brother is James, who is also D.W.'s friend and classmate. She enjoys listening to the heavy metal band Mütakrüde and taking care of James.

Personality and skills
In earlier episodes, she can be sarcastic, selfish, and a bigger bully than Binky at times. Despite this, she still gives great advice which was revealed in "Don't Ask Muffy" and even described as her hidden talent in "Brain's Chess Mess", and she helps her younger brother James. In "Mind Your Manners", she gives some practical advice to the Tibble twins, while showing courtesy to another customer. However, Molly has a complete change of heart in "The Last Tough Customer" after witnessing her brother James bullying Amanda Hulser, and resolves to stop being mean to others. Molly is very skilled in skateboarding, being shown to enjoy practicing at the skatepark and using it as her main means of transport outside school. She is also a talented artist, as seen in "The Agent of Change" when she joins up with Muffy and Francine to create an animated movie after being annoyed at there being no popular movies with female leads, and also after Binky makes fun of them for wanting a female lead, saying that a female lead is just boring.

Appearance
Molly is a tall, thin rabbit with long ears and a white complexion. She wears a sleeveless blue denim vest with ripped jeans and red sneakers. Her hair is always let down and blocks her eyes, though they have been seen at least once.

History
In the episode "The Last Tough Customer", it was revealed that she was bullied as a kindergartner. That event marked the day Molly became a bully. Before she got bullied, her hair was put up in a bun on top of her head, giving her the name "Muffin Head".

James MacDonald
James and Molly seem to be quite close. James has been shown to turn to his older sister for advice on many occasions, and look up to her. In "The Last Tough Customer" she stopped James from becoming a bully after witnessing him bully Amanda at a water fountain and promising to stop her mean ways.

Arthur Read
Arthur and Molly are shown to be friends in a few episodes, but usually they aren't by the ends of the episodes. This public attitude, however, is just a cover for their secretly staying friends.

The Tough Customers
Molly seems to like the Tough Customers very much. In "The Last Tough Customer", she didn't want the Tough Customers to be nice. Also, in "The Law of the Jungle Gym", she didn't want to give the jungle gym to Muffy for her photos. She is the most loyal Tough Customer and is possibly tougher than Binky, Rattles, and Slink, who each have a secret, soft hobby.

Appearances
{{Scroll box|content = ====Season 1====
 * 10301. "D.W. All Wet" {{c|first appearance}}
 * 10602. "Arthur Accused!" {{c|cameo}}
 * 10701. "Arthur Goes to Camp" {{c|cameo}}
 * 11101. "Arthur's Baby" {{c|cameo}}
 * 11202. "Arthur's Lost Dog" {{c|cameo}}
 * 11701. "Meek for a Week" {{c|cameo}}
 * 11702. "Arthur, World's Greatest Gleeper"
 * 12101. "Sue Ellen Moves In" {{c|cameo}}
 * 12301. "Bully for Binky"
 * 12502. "Arthur Cleans Up"
 * 12802. "The Scare-Your-Pants-Off Club" {{c|cameo}}
 * 12901. "My Club Rules" {{c|cameo}}

Season 2

 * 20101. "Arthur Meets Mister Rogers"
 * 21102. "Buster Hits the Books"
 * 21401. "Sue Ellen's Lost Diary"
 * 21702. "Arthur the Loser"
 * 21802. "D.W.'s Very Bad Mood"
 * 22001. "How the Cookie Crumbles"

Season 3

 * 30501. "The Chips are Down"
 * 30502. "Revenge of the Chip"
 * 30602. "Meet Binky"
 * 30702. "Dad's Dessert Dilemma"
 * 30801. "Popular Girls"
 * 31102. "Arthur's Almost Live Not Real Music Festival"

Season 4

 * 40102. "Arthur's Big Hit"
 * 40502. "The Rat Who Came to Dinner"
 * 40701. "Binky Barnes, Wingman"

Season 5

 * 50702. "Pet Peeved"

Season 6

 * 60402. "Brother, Can You Spare a Clarinet?"
 * 60701. "The Boy with His Head in the Clouds"
 * 60901. "The Good Sport"

Season 7

 * 70302. "Don't Ask Muffy"
 * 70702. "Buster's Amish Mismatch"
 * 70901. "Prunella Sees the Light"

Season 8

 * 80402. "D.W., Dancing Queen"
 * 80501. "Vomitrocious"

Season 9

 * 90302. "The Law of the Jungle Gym"
 * 90601. "Arthur Makes Waves"
 * 90901. "D.W. Beats All"
 * 91001. "Binky Goes Nuts"
 * 91002. "Breezy Listening Blues"

Season 11

 * 110102 "Germophobia"
 * 110201 "Arthur Sells Out"
 * 110202 "Mind Your Manners"
 * 110401 "Phony Fern"

Season 13

 * 130100 "The Great MacGrady"
 * 130202 "Kung Fool"
 * 130602 "D.W. Swims with the Fishes"
 * 130902 "The Pride of Lakewood"
 * 131001 "Looking for Bonnie"

Season 14

 * 140201 "The Agent of Change"
 * 140202 "D.W. Unties the Knot"
 * 140302 "The Play's the Thing"
 * 140501 "Tales of Grotesquely Grim Bunny"
 * 140601 "Follow the Bouncing Ball"
 * 140801 "Arthur Unravels"

Season 15

 * 150201 "I Wanna Hold Your Hand"
 * 150301 "Buster's Secret Admirer"
 * 150302 "The Last King of Lambland"

Season 16

 * 1601. "Based on a True Story"
 * 160601 "The Last Tough Customer"
 * 160602 "Brain's Chess Mess"
 * 160702 "Brain's Biggest Blunder"
 * 160801 "Buster's Book Battle"
 * 160902 "Sue Ellen Vegges Out"
 * 161001 "So Funny I Forgot to Laugh"

Season 17

 * 170501. "All Thumbs"
 * 170802. "Crime and Consequences"

Season 18

 * 180102. "D.W. & Bud's Higher Purpose"
 * 180202. "Surprise!"
 * 180301. "The Case of the Girl with the Long Face"
 * 180402. "The Tardy Tumbler"
 * 180601. "Whip. Mix. Blend."
 * 180702. "Messy Dress Mess"

Season 19

 * 1902b. "Wish You Were Here"
 * 1906a. "Maria Speaks"
 * 1907a. "Carl's Concerto"
 * 1907b. "Too Much of a Good Thing"
 * 1910. "The Last Day"

Season 20

 * 2001a. "Buster's Second Chance"
 * 2001b. "Arthur and the Whole Truth"

Season 21

 * 2104b. "Arthur Takes a Stand"
 * 2105a. "Slink's Special Talent"
 * 2105b. "Take a Hike, Molly"

Specials

 * "Arthur - It's Only Rock 'n' Roll"
 * "The Rhythm and Roots of Arthur"
 * "Arthur's First Day"

Books

 * Arthur, It's Only Rock 'n' Roll}}