This is such a disturbing novella - I've read it before, several times over the years, and I even wrote a short story about Gregor's sister Grete recently, and her attempts to get over her loathing of insects, which was published in an anthology last year (I think it was last year).

It's just so weird. Gregor wakes up, an insect, and somehow his life gets worse from there. I note this particular translation comes straight out and says he's a cockroach, but I'm pretty sure I read somewhere that the original untranslated version didn't specify what sort of insect he was. It just leaned into the aversion factor, hard, and everyone automatically filled in the blanks with "cockroach." Well, they are revolting. I'm mad on nearly all animals, but I cannot warm to cockroaches. They skitter. They're filthy. (Do they? Are they? Or have I just tapped into a prejudice that's as immovable as it is unfair?) 

Anyway, it's clear to me that Kafka knew what he was doing when he tapped into that shared, unthinking repulsion. It's very clever, and it works.