Mr. Samsa is the name given by Nny to a series of normal cockroaches that live in his basement, which he believes to be a single immortal cockroach that he must repeatedly kill. To Johnny, Mr. Samsa represents complete desensitization and unemotional thinking, a state for which Johnny begins a quest at the end of the series. The insects are normal bugs with no ties to the supernatural entities in the series.
They are named after the main character, Gregor Samsa, of Franz Kafka's short story "The Metamorphosis." The main premice of the novella is Gregor transforming into a "terrible vermin," usually envisioned as a giant cockroach.