Bernard began as a janitor for the Rescue Aid Society and helped retrieve Penny's message from the bottle. Miss Bianca then took him with her to rescue Penny from Madame Medusa. He is a very nervous mouse and is known to be superstitious and afraid of flying. He is later made a full member of the Rescue Aid Society and Miss Bianca's partner.
Bernard plans to propose to Miss Bianca, but he is continually thwarted by circumstance. While initially intimidated and jealous of Jake, Bernard becomes more confident and courageous, following Jake's example. He also is shown to be both clever and caring while caring for Marahute's eggs. Miss Bianca agrees to marry him.