The Metamorphosis (German: Die Verwandlung) is a novella written by Franz Kafka which was first published in 1915. One of Kafka's best-known works, The Metamorphosis tells the story of salesman Gregor Samsa who wakes one morning to find himself inexplicably transformed into a huge insect and subsequently struggling to adjust to this new condition. The novella has been widely discussed among literary critics, with differing interpretations being offered. One day, Gregor Samsa, a traveling salesman, wakes up to find himself transformed into a giant insect (the most common translation of the German description ungeheures Ungeziefer, literally "monstrous vermin"). He reflects on how dreary life as a traveling salesman is. As he looks at the wall clock, he notices that he has overslept and missed his train for work. He ponders the consequences of this delay. Gregor becomes annoyed at how his boss never accepts excuses or explanations from any of his employees no matter how hard-working they are, displaying an apparent lack of trusting abilities. Gregor's mother knocks on the door, and he answers her.

ある朝目ざめると青年ザムザは自分が1匹のばかでかい毒虫に変っていることに気づいた。以下、虫けらに変身したザムザの生活過程がきわめて即物的に描かれる。カフカ(1883‐1924)は異様な設定をもつこの物語で、自己疎外に苦しむ現代の人間の孤独な姿を形象化したといえよう。20世紀の実存主義文学の先がけとなった作品である。