If you haven’t read the Nikolai Gogol short stories yet, you should. They truly are timeless, and so amusing! They are available online for free, as they are not subject to copyrights any more.
These are illustrations of a short story called ‘Diary of a Madman’. They follow a low-ranked government employee, who goes bonkers. He first breaks into his boss’s apartment to steal his dog’s imaginary letters. Then he becomes persuaded he is the Spanish king, and ends up in a mental asylum, where he has to stop the moon from coliding with the earth.