In the introduction to this story (The Tale of Mr. Tod), Potter announced that for a change she was going to write about disagreeable people. Certainly Tommy Brock the badger is one of Potter's most ruthless villains and Mr. Tod the fox is not exactly a pleasant person either.
Because the food supply is limited, Tommy Brock kidnaps Benjamin Bunny's children, and heads off to Mr. Tod's house, whose kitchen he'll "borrow" to make a rabbit pie in the morning.
When Mr Tod catches Tommy Brock trespassing again, he decides to take revenge. The elaborate contraption he rigs up to kill his long-time enemy was inspired by details in several different Uncle Remus stories.