C. H. Greenblatt voiced his adult self in the last episode. In the final episode, “Chowder Grows Up” Chowder takes over the Catering Company, has his own apprentice, and marries Panini.

What is meant by breaking down the fourth wall?

When the fourth wall is broken, it means the characters within the media are allowing the audience to become one with it, most commonly being referred to directly as the audience or, less often, characters subtly referencing the fact that they're inside a form of media. ...

What does Panini say to Chowder?

Chowder: (in regular voice) Would I! (takes cookie) (frowns) Aw, man! ☀(Panini, sipping juice from a box, stares lovingly at Chowder, who tries to get away from her, but she's blocking his passage.) Panini: Hi, Chowder!