Mack is portrayed by Lincoln Melcher.
Mack is smart, creative and well-rounded. He is shown to be a very nice guy. The quads consider him to be cool and mature.
Dawn reveals to Josie that she has a crush on Mack and thinks that he has a nice neck. With Josie's encouragement, she asks Mack out for the upcoming Halloween Dance. Mack accepts and Dawn makes them wear small costumes so that they be able to dance together. Mack is please that Dawn want to dance with him, and Dawn reveals that she's a good dancer. Dawn starts to dance to demonstrate to Mack. Mack starts dancing like her. At first Dawn thinks he's dancing goodly to make her feel better and realizes that Mack is a good dancer too and is doing his best.
During a quadfession session, Dawn confesses to her brothers that she has a crush on Mack. When they start singing "Dawn loves Mack!" a parrot copies them and sings the same in public exposing Dawn's crush on Mack to the entire school. This leads to Mack and Dawn having an awkward moment in the lockers when Mack realizes the truth. Dawn eventually sends out a text to the entire school admitting that she has a crush on Mack.
It is revealed that Mack is a very good puppeteer when Dawn quits the quads' puppet show and partners with Mack. The boys try to intimidate Mack into not hanging out with Dawn but Dawn makes sure they won't succeed. Before the puppet show, Dawn leaves Mack to go and fight with her brothers. Dawn is confident the she and Mack will win the puppet show since Mack wins every year and has gone to a sleep-away puppet camp. However, before the show, Dawn leaves Mack so that she can fight with her brothers some more. During that time, Mack puts on an amazing puppet show, surprising everyone. He ends up winning the competition after the Harper Quads ruin everything.
Mack is having fun pranking Principal Tarian and brags about it to the quads. At first, Dawn doesn't believe that Mack is capable of the pranks but eventually admits it. Later on, when the quads run out of drama for their quad court, they decide to setup Mack. They place their dad's candy golf-balls in one of the student's locker with a note of Mack's face that says "Mack Attack!" When the balls spread on the hallway and catch the principal's attention, he concludes that Mack did it. The quads attempt to confess doesn't work out because the principal assumes that they are just trying to protect Mack. Eventually, they manage to prove that Mack is innocent by holding a quad court.
Mack makes a pact with Dawn to go see an upcoming movie together as "movie buddies." Dawn is planning on being accompanied by her parents as usual but "Cool" Moses makes them insecure by saying that going to movies with parents is uncool. When Tom and Anne refuse to let Dawn go with Mack alone, Dawn calls Mack to cancel the movie date by pretending to be sick. Since the quads don't want to be seen by Mack or other classmates, they convince their parents to go see a different movie at a different theater. They find Mack at the theater too and are even shocked to see him going into the movie they had planned to see together. Dawn is mad that Mack betrayed their movie pact and went to see the movie alone. She sends Mack and angry-Dawn voicemail but after realizing what she's done, she tries to get Mack's phone to delete the message and control the damage. They later realize that Mack had gone to that auditorium by mistake. Like the quads, it turns out that Mack had gone to that theater complex to hide from Cool Moses and other classmates so that he doesn't seem uncool for going with his parents.
Dawn wants to go the upcoming Renaissance Fair but doesn't want to go with her brothers because they're so immature. She says Mack is more mature and asks him to go with her. She makes it clear that she and Mack aren't dating and they're going just as friends. So, she invites Mae and Miles to join along. However, when she continues bragging about being more mature than her brothers, the quads settle for a mature-off to prove which one of them is more mature. Dawn tries to get Mack to hold hands with her and look into each other's eyes in order to complete, Dooley's Triange of Romance challenge and prove that she's more mature. The boys try to sabotage Mack and Dawn by tricking Mack into putting on a heavy knight costume if he wants to impress Dawn. Dawn realizes that the boys got to Mack and so, she puts on the knight armor and goes after the boys. Later, Mack is disappointed to realize that he was forced to wear that costume for a silly contest. Dawn apologizes to Mack and admits this she's ready to date yet.
Mack met Dawn at the Store along with her borthers and their friends. That there's a werewolf's attacking them. But Squisshy Paws's in his dragon suit at the end.
Dawn ask Mack to go on a date during skydiving and they hold hands and crash into their house along with Nicky, RIcky, Dicky, and Mae.
Main Article: Dawn and Mack
- Mack is Dawn's classmate and couple. In the episode "The Secret," it is revealed that Dawn has a crush on Mack. However, from a viewers' perspective, it's very likely its mutual. It's shown in Ye Olde Hand Holde, that he returns Dawn's feelings. They went on their date together forever and ever.
- Scaredy Dance
- The Secret
- Piggy, Piggy, Piggy & Dawn
- Unhappy Campers
- Quad Court
- The Quad-Plex
- Nicky, Ricky, Dicky & Sicky
- Mission: Un-Quaddable
- The Tell-Tale Art
- Ye Olde Hand Holde
- Tween Wolf
- Cementing the Quads' Legacy
- Nicky, Ricky, Dicky & BeyDawncé
- Quadcodile Dundee
- Lasties with Firsties
- Mack went to a SleepAway Puppet Camp and Camp Bear Claw.
- In Ye Olde Hand Holde, it is revealed that Mack's middle name is Albert.
- He has made 15 appearances on the show.
- Mack's full name is possibly a pun on the nutritional fruit "macadamia".
- he is played by Lincoln Melcher who played Griff Jones in Bunk'd