Role in film
He is the the main antagonist in the film. He appears near the end of the film, when the main characters are sent to Ernie's Disposal, an automotive junkyard. During the song Worthless, the Giant Magnet mercilessly kills one of nine of the Junkyard Cars, picking them up and dropping them onto a conveyor belt leading to a Crusher, as he crushes them into tiny cubes, while Toaster and his fellow appliances try to find cover from the Giant Magnet. Unlike the Junkyard Cars, he doesn't have (even) a happy expression or a sad one. Therefore, he has only a mad expression.
Being a cold and uncaring machine created to destroy, the Giant Magnet shows no sympathy for his victims and has no regrets about killing them. Although the Magnet is simply performing its job, like Elmo St. Peters, to destroy the cars, it later chases the appliances, deliberately picking up every object (or more) they hide under. When the Master arrives at Ernie's Disposal to retrieve his appliances, he grabs onto them just as the Magnet picks them up, being lifted into the air and dropped onto the conveyor belt along with them. As they are about to be killed by the crusher, Toaster jumps into the workings of the machine, using his own body to jam its gears. Crusher is disabled just in time, and the Toaster is repaired by the Master.