Cat and Mouse, a novella by Günter Grass, is set in Poland during World War II. The mouse in the title, symbolizes a socially awkward and eccentric boy named Mahlke, who has an enormous Adam's apple, which he is insecure about. The cat in the title is the embodiment of various "predators" in Mahlke's life: society, the Nazi Party, school, peers, and his part-bully, part-friend, Pilenz, who is also the narrator of the story.

Another theme of the story is Mahlke's obsession with the Iron Cross, which is rooted in his desire to become someone people respected. This is due to his insecurities. He literally and figuratively wants to hide his abnormally sized Adam's apple. Even in an earlier section of the story, Mahlke impresses the other boys by being the best swimmer in the group. This gives Mahlke a taste of what it's like to be admired rather than mocked or bullied.

A sub-theme in the story is the atmosphere of war in Continental Europe. The Nazi Party—which infamously invaded Poland—is a lingering presence in the narrative, and is one of the components of the "cat" that leads to Mahlke's death in the end.

The old minesweeper where Mahlke found a secret room is also symbolic of a mouse's lair, where Mahlke keeps his prized possessions. Like a mouse, he is a scavenger. Like a mouse or rat, Mahlke was shunned by society and he died in the dark waters the way a dead mouse is disposed of in a trash can or sewer.