Fantastic Mr. Fox is an allegory which warns against greed. The three farmers themselves are personifications of greed: Boggis and Bunce are hyperbolically fat due to their repulsive diets, supplied by their large and successful farms. Bunce’s diet of mashed goose livers stuffed into donuts gives him “a tummy-ache and a beastly temper” (3). All three men are “as nasty and mean as any men you could meet” (2). Roald Dahl suggests that a life spent pursuing financial wealth and gorging on one's riches leaves a person miserable—angry and alone with only material things to show for it.

Mr. Fox’s growing greed manifests as boldness. He only takes “three plump hens” from Boggis’s thousands (3), as this haul is enough to feed his hungry family. However, in Bunce’s storehouse, Mr. Fox instructs his children and Badger to take four ducks, a few geese, some ham and bacon, and carrots. This change in thievery is fueled by Mr. Fox deciding to feed his friends with a decadent spread provided by himself.

Mr. Fox’s growing greed is solidified by his decision to break into Bean’s cellar, as adding cider to the animals’ feast is unnecessary for survival.