Plot
Former supervillain and undercover Anti-Villain League (AVL) Agent Gru attends a class reunion at his alma mater Lycée Pas Bon where he reunites with Maxime Le Mal, a former classmate of his who has a feud with Gru who he believes stole his talent show act. During the ceremony, Maxime reveals he has enhanced himself with cockroach body parts, but Gru has him arrested by the AVL. Helped by his girlfriend Valentina, Maxime escapes prison to get revenge on Gru and reveals his new invention: a ray gun that transforms people into cockroach hybrids, which he plans to use specifically on Gru's infant son Gru Jr.
In their new well-off residential town, Gru and his family meet their new neighbors, the Prescotts, and their teenage daughter Poppy. Poppy, an aspiring villain, recognizes Gru from his former villainous career and threatens to blow his cover unless he helps her pull a heist to steal Lycée Pas Bon's honey badger mascot Lenny. With the help of two Minions and Gru Jr., they successfully steal Lenny from the school, unaware that Lenny's collar contains a tracking device. The school's principal Übelschlecht identifies Gru via security camera footage and contacts Maxime to inform him about Gru's whereabouts.
The next day, while Gru and Lucy are away at tennis practice with Poppy's parents Perry and Patsy, leaving Poppy to watch over the girls and Gru Jr., Übelschlecht visits the safe house to interrogate them about Gru, which makes Poppy promptly walk away with Lenny. Gru and Lucy then rush back home after being alerted by Margo and they fight Übelschlecht. Lucy also signals the AVL who calls the Mega Minions out of retirement to stop Maxime. In the havoc, however, Gru Jr. leaves the house and is spotted by Maxime and Valentina, who kidnap him. Lucy and the girls stay behind to handle Übelschlecht as Gru decides to save his son with help from Poppy.
Dr. Nefario reverses Gru Jr.'s transformation. Sometime later, Gru visits Maxime in an AVL prison to talk and settle their differences. The rivals then put on a performance of "Everybody Wants to Rule the World" for the prisoners, which include villains from the past, while Poppy is accepted at her dream school Lycée Pas Bon.
