Benjamin "Benji" Applebaum is a magician and a recent member of the Treblemakers, recruited shortly before the ICCA Finals after the loss of their former leader Bumper. He shares his dorm with Jesse Swanson, whom he becomes good friends with. At the end of Pitch Perfect 2, his love interest is Emily Junk.
Benji is a 'certified illusionist', as stated in an awkward meeting with The Treblemakers, whom he idolizes.
Seeing their performance at a Mall of America years before, he is a particular fan of frontman Bumper Allen. Benji is dismissed by Bumper in their initial meeting and although giving a high quality audition, is rejected entry into the group because of Bumper's opinion of him.
Days before the ICCA Finals, Bumper leaves the group to "sing backup on John Mayer's new CD." Taking initiative, Jesse gets Benji into the Trebles, even arranging B.o.B.'s "Magic" to feature Benji on lead vocals as a homage to his roommate's hobby
Benji is known to be a fan of the Star Wars series and has many prop replicas in his bedroom. He also has illusion props, including a mysterious black box with swords poking out.
At the New Student orientation, Benji is first seen peforming with The Treblemakers. He introduces himself to new Freshman Emily after she mentions her dream of being a Bella. Being mesmerized by her, he tries to talk to her. This backfires when a "pickup line" he uses freaks her out more than interests her - "I just wanna put you in a box and cut you in half". Jesse interjects, adding some explanation to this by informing Emily that Benji does magic.
Benji is a bit shy around the Bellas, but awed and over-excitable around the Treblemakers. He does feel remorseful for the Bellas when they do not advance in the 2012 ICCAs, as he reports the underage lead singer to the officials.
Jesse and Benji first meet in their dorm room where Benji has just finished re-decorating his half of the room. Jesse is slightly disturbed by this but soon they become friends. When Benji is showing Jesse around, he says, "There is only one group on this campus worth joining," and looks toward the Trebles. When Bumper leaves the Trebles and Jesse takes the lead, he convinces the Trebles to let Benji in. At the end of the film Benji and Jesse are seen together running the Trebles. All the Trebles are singing Bright Lights, Big City when Benji comes out and starts singing Magic.
Benji knows Beca only through their mutual friend Jesse. He is sympathetic to her plight, however they have little-to-no interaction between each other.
In Pitch Perfect 2, the new freshman member of the Bellas and a legacy, Emily Junk, becomes Benji's love interest. He repeatedly has trouble talking to her, eventually winning her over by attending the world championships with Jesse just to cheer her on, where they kiss. It is unknown whether or not they are still dating in the third film.
Benji: "I'm also super into close-up magic." (Produces hamster from sleeve) Jesse: "Dude, that's awesome... how long has that little guy been in there?" Benji: "Several days."
Benji: "Deal... although, I don't know what you mean by weird." (Bird flutters onto shoulder) Benji: "Got it."