Bob Ewell is considered a static character who certainly does not undergo moral development throughout the novel. Bob Ewell is portrayed as Maycomb's most despicable citizen—a notorious alcoholic and abusive father.
In addition to the fact that Bob Ewell is a lazy alcoholic, he is also an ignorant racist who beats his daughter after he witnesses her kissing Tom Robinson. Bob then forces Mayella to corroborate his story regarding the events that transpired on the evening of November 21st. During the Tom Robinson trial, Bob Ewell displays his disrespectful, vulgar personality while on the witness stand and proceeds to tell the jury a fabricated story.
Following the trial, Bob Ewell is embarrassed that Atticus exposed the truth and vows to get revenge. Bob Ewell proceeds to spit in Atticus's face, trespass on Judge Taylor's property, and even intimidates Helen Robinson on her way to work. At the end of the novel, Bob Ewell demonstrates his completely immoral, malevolent nature by attacking Jem and Scout on their way home from the Maycomb Halloween festival.
Bob Ewell's murder attempt proves his lack of moral development and underscores his evil personality. Unlike Scout, who morally develops into a compassionate, tolerant girl with perspective, Bob Ewell remains wicked, callous, and cruel. Overall, Bob Ewell does not morally develop and remains a heartless, malicious character throughout the story.