In the cutscene involving the Plumber and Clank inside Clank's memory banks, the Plumber is trying to find a clog inside a large green pipe. When he tells Clank to jump in the pipe, Clank asks if the Plumber's coming too, to which he replies,"Plumbers don't just go diving down strange pipes all willy-nilly, that'd be ridiculous!" This statement, along with the green pipe, is a reference to the Mario Bros. series, and his affinity for using pipes for transportation.