Jam is a grape worm who only appeared in the episode "The Grape Worm".
In the beginning of the episode, Chowder ate grapes off a vine infested with worms, and soon after Jam appeared, living in Chowder's belly button. Chowder thought Jam was his inner voice. He can also tell Chowder what to do but only because he is loud, annoying and direct. Jam is neaurotially obsessed with hygiene and considers almost anything to be disgusting and dirty including all types of food and unfreshened air. Jam did stuff like make Gazpacho's customers angry, spray Kimchi with clean spray, and forbid Chowder from even the most basic needs such as eating or going to the bathroom. Chowder eventually manages to scare Jam out of him by going to the foothills, where grapes get crushed by giant mechanical feet to produce juice. Jam was horrified that Chowder would do anything so dangerous, and soon jumped out of Chowder's stomach. His departing words were, "You will always have a part of me close to you heart. No, really. because I laid eggs." When Jam went away in the wind he landed in Gazpacho, who was floating nearby in a hot air balloon. Jams fate is unknown because when Gaspacho is in the next episode, Jam is not with him.
Jam is similar to a tape worm.
He is voiced by Bobby Moynihan.