The answer is: Gregor transforming into an insect.
Franz Kafka´s novella, <em>Metamorphosis</em>, presents us with his famous character, Gregor Samsa, who one day, at the very beginning of the story, woke up to find himself, for no apparent reason, turned into a horrible, and hard to define, kind of bug.
Although Kafka´s work is not usually characterized as surrealist, there are passages where his treatment of absurd themes certainly exploit oneiric, fantastic, unexplainable, and spontaneous manifestations of the imagination (all traits of surrealism) for the benefit of the narrative.