Following the Tom Robinson trial, Bob Ewell feels embarrassed and harbors a grudge against Atticus, who presented the ugly truth regarding his and Mayella's actions on the evening of November 21st. Bob Ewell vows to get revenge on Atticus for presumably ruining his reputation, which was never stellar in the first place, and even spits in his face when Atticus is leaving the post office.
In chapter 23, Bob approaches Atticus outside of the post office and threatens to kill him. Atticus refuses to fight Bob Ewell, who ends up spitting in his face and cursing at him. Bob Ewell's actions illustrate his despicable, ignorant nature and once again reveal his malevolent personality. Bob Ewell's actions also reveal that he is an angry, malicious person, who lacks respect and integrity. Unfortunately, Bob Ewell continues to seek revenge on Atticus and ends up attacking his defenseless children on their walk home from Maycomb's Halloween festival.