Animals
Like many of Shakespeare's plays, animals figure heavily into the language of Julius Caesar. Usually, animals appear through similes and metaphors as characters frequently compare Caesar to various predators and prey. In Act One, for example, Cassius compares Caesar to a blood-thirsty lion, while later Antony compares Caesar to an innocent deer after his murder. The prevalence of animals throughout the play helps showcase different characters' perspective on whether Caesar was beneficial or detrimental to Rome.
Calpurnia's Dream
The day that Caesar is supposed to go to the senate (and the fateful day he is murdered), Calpurnia warns him that she had, the previous night, had a dream in which Caesar was spouting blood. The vivid description mirrors the actual assassination of Caesar to follow, as he is stabbed multiple times by conspiratorial senators.
Ghosts
Ghosts are important images in the plot of Julius Caesar, as they function as omens that predict unfortunate circumstances. The night before Caesar is murdered, Casca encounters a woman who claims to see burning men that nobody else can see. Toward the end of the play, Brutus is haunted by a ghost whom he believes to be Caesar himself. These visions of ghosts were not uncommon on the early modern stage, which often employed the supernatural as a way to titillate audiences and foreshadow action to come.
Weather
Bad weather, like ghosts, becomes a central image in the play, especially leading up to Caesar's assassination. The night before Caesar's murder, there is an intense storm that seems to shake the whole the city. Casca eventually interprets the storm as an omen of Caesar's meteoric rise, thinking it reflects the havoc Caesar will wreak on the Roman people if he remains in power. Audiences might have a better idea, however, that the storm predicates civil war in the wake of Caesar's murder.