Despite being the calmest in their younger years, upon hitting Hogwarts, Scorpius, Albus, and Rose became the biggest pranksters the school has ever seen. James, who Professor McGonagall had been expecting to be the obnoxious one, was surprisingly respectful and very obviously took after his mother more than anyone else, especially how she was in her younger years. So, when Albus came to Hogwarts with Hermione and Ron's eldest child Rose, she had been expecting the same outcome. Oh how she was wrong. After meeting Scorpius Malfoy on the train ride to Hogwarts, the three of them had concocted a plan to break out of their comfort zones and wreck havoc in the halls of Hogwarts.
Rose Evangeline Granger-Weasley: The Mastermind.
She seems innocent enough, but she comes up with the cunning, exploitative plans for pranks. She typically stays out of trouble and despite Professor McGonagall knowing that Rose is the one behind everything, she has no proof, therefore, cannot punish her.
Scorpius Hyperion Malfoy: The Executor.
He follows through with Rose's plans and even adds his own last minute touches to the pranks. Having set the record for the most detentions for pranks since Fred and George Weasley attended Hogwarts, he has his own official chair with his first and last name on it, written on a small plaque.
Albus Sirius Potter: The Accomplice.
Along with Scorpius, he follows through with the plans, although, he serves more than a look out than anything else. He watches for teachers and other students with the Marauders Map and supplies the Cloak of Invisibility for he and Scorpius to sneak around in. James had originally owned both, but he knew Albus had better use for it. (Hey! Even if he is the "good" Potter, he can push some of the fun along...) Like Scorpius, he tends to add his own touch to the pranks.