There is descriptive imagery throughout The Metamorphosis. The novel is written in a very realistic style, almost deliberately disgusting with its descriptions of the giant insect, the house, and its inhabitants. In the very first lines, many examples of imagery are available:
One morning, when Gregor Samsa woke from troubled dreams, he found himself transformed in his bed into a horrible vermin. He lay on his armour-like back, and if he lifted his head a little he could see his brown belly, slightly domed and divided by arches into stiff sections.
(Kafka, The Metamorphosis, gutenberg.org)
Gregor's dreams are "troubled," with the resulting image that he did not sleep well. His transformation is into a "horrible vermin," which could be almost anything unpleasant, but is revealed to be some sort of insect with an "armour-like back" and "brown belly." His belly is "domed" and "divided by arches," giving the sensation of something creepy, something that people would not want to see and touch. In fact, most insects have textures that people instinctively don't like to see or touch, and every description of Gregor afterwards plays on this theme, with his movements and strange sounds described in great detail. Every detail about Gregor's body is an example of imagery, as are many of his thoughts, which bring to mind the worries and fears that he feels every day.