Since Verwandlung does not exclusively mean metamorphosis, it really leaves to the reader to determine what exactly is the subject of the metamorphosis/transformation. By saying that, I almost directly position myself to the side of the “death of the author”, though I have no credential of claiming to be a post-structuralist; what I would like to do is just to keep a record of how I interpret this work.
The transformation has been suggested to be presented by the physical metamorphosis of Gregor into the insect/beetle/bug, by the transformation of the attitude of Grete, and also, by the altering mental state of Gregor. I have no objection to any of these. Sincerely, the transformation of Grete is distinctly noticeable and the theory itself is very convincing.
However, instead of asking what the metaphor is about, what is the subject of the metaphor, and which character represents what, I want to know what has been genuinely transformed?
The entire story to me, is actively mourning the vanish of love.
It doesn’t matter what kind of insect, or not insect, he turned into, or that his didn’t even transform to anything at all, the point is that he became a burden. This burden, partly the result of not able to communicate, turns this into a tragedy, rather than a fable. He is not the ugly duckling, and there is no positive insight in it. I believe Kafka simply wrote down what he thought was real, that love, no matter how much you have, as Gregor tried to provide Grete the opportunity to be a musician, will (I would say may) degrade, it will be forgotten. He could simply write a story about how someone got leprosy and his family turned away from him but it can be much scarier than that. Because seeing love turning into nothing is one of the scariest thing ever in its nature, and that we just don’t even want to look at it.
The Fleeting Moments 