Gregor
Gregor, the main character of Kafka's The Metamorphosis, is a very kind, caring, and intelligent individual. However, he is abnormally loyal to his family members, all of which do not work in the beginning of the story, and is their only source of considerable income.
It's revealed at the beginning of the story that Gregor is currently working extremely hard to pay off his family's debt to his employer, which was accumulated after their family business fell apart. When Gregor transforms into a vermin and loses his usefulness in the family, the true dark side of his relationship with his family members is revealed, as they struggle to deal with his new appearance and his father tries to dispose of him in Part II.
Grete
Before Gregor's transformation, Gregor and Grete had a more prominent bond than Gregor had to his parents. As a result, Gregor's sister, Grete, probably has the strongest relationship with her brother, as she is the only one that takes care of him after his transformation and Gregor. Although his mother does feel pity and a need to help him, it isn't until later in the story that this develops.
By Part II of Kafka's story, Grete has begun her own transformation into a young woman, not a vermin. Over time, as she begins to develop, she begins to feel less and less pity towards Gregor. By the end of Kafka's story, she stops taking care of Gregor completely.
Mom
Although Gregor's mother, Mrs. Samsa, is a very affectionate and dutiful mother, she doesn't show any affect or pity until later in the story, during part II. This is due to the fact that she is initially convinced by Gregor's sister and father to avoid contact with her son and to stay out of the room in which he resides throughout the story. On top of that, she faints whenever she sees Gregor during the story, making it very hard to determine her exact feelings towards Gregor, other than shock.
Mrs. Samsa's feelings of pity towards her son is projected to the reader when she saves Gregor from his outraged and frustrated father. Because she has to beg for Gregor's life during this section of part II, it's also obvious that she is very submissive towards her husband and that she follows any order given to her by him. She's also very quiet throughout the story, even when she is present in the story's third-person view.
Mr. Samsa
Gregor's father, Mr. Samsa, despite being taken care of by Gregor in the past (Finances), does not take care of Gregor at all during the story, and it is assumed that they don't have a very strong relationship. On top of that, he is very consumed by money, as instead of paying off their debt with Gregor's money he saves it, and is very impressionable. The reader is provided evidence of this when Gregor's father's business falls apart. Instead of working to pay off his debt or support his family, he decides not to work anymore at all, forcing Gregor to compensate for his laziness.
When Gregor's father finally gets a job, when Gregor transforms, he becomes very prideful and also feels empowered by his new uniform. This is reinforced by the fact that he never takes off his uniform, except in certain situations.
