Tom is presented negatively throughout the novel. He is introduced as something of a brute and bigot and his infidelity is a central aspect of his character from the beginning to the end of the novel.
Tom is described as "hulking" and possessing a "cruel body". The negative associations continue as Tom quotes from a racist screed that he has been reading and which has won him over, "The Rise of the Colored Empires". All in all, Tom is rather thoroughly derided in Nick's account.
Tom Buchanan is the villain of this novel and has Nazi-like theories of race.
Tom is shown to be violent toward Myrtle in his relationship with her, his mistress, and rude to her husband even as he cheats with his wife. In the end, Tom manages to stand by Daisy but does so in the most cowardly way available to him - by running away with her to escape any blame for Myrtle's death and also turning the attention to Gatsby.