Act I

Why, man, he doth bestride the narrow world
Like a Colossus, and we petty men
Walk under his huge legs and peep about
To find ourselves dishonorable graves.  (1.2.136–139)

In these lines, an envious Cassius compares the ascendant Caesar to the Colossus of Rhodes, an ancient statue of the god Helios that was believed to have straddled an entire harbor so that ships could pass through its legs; next to such a giant, says Cassius, he and Brutus are just tiny, insignificant men.

However he puts on this tardy form.
This rudeness is a sauce to his good wit,
Which gives men stomach to digest his words
With better appetite. (1.2.295–298)

Here Cassius uses a metaphor to explain that the seemingly dimwitted Casca is actually quite clever; he merely pretends to be daft, serving up his words with a simple sauce that makes others hungry to hear his ideas.

I know he would not be a wolf
But that he sees the Romans are but sheep.
He were no lion were not Romans hinds. (1.3.105–107)

In this series of metaphors, Cassius downplays Caesar’s greatness, arguing that Caesar only became a top predator—a wolf and a lion—when he realized that Romans were such easy prey—sheep and hinds (deer).

Oh, he sits high in all the people’s hearts,
And that which would appear offense in us,
His countenance, like richest alchemy,
Will change to virtue and to worthiness. (1.3.159–162)

In this simile, Casca compares Brutus’s reputation to alchemy, the goal of which was to transform common metals into gold; likewise, the conspirators seek Brutus’s support because they believe his reputation will transform their criminal plot into a virtuous and worthy endeavor.

Act II

And, to speak truth of Caesar,
I have not known when his affections swayed
More than his reason. But ’tis a common proof
That lowliness is young ambition’s ladder,
Whereto the climber upward turns his face.
But when he once attains the upmost round,
He then unto the ladder turns his back,
Looks in the clouds, scorning the base degrees
By which he did ascend. So Caesar may. (2.1.19–27)

In this extended metaphor, Brutus rationalizes his belief that Caesar must be killed even though he has not yet abused his power, comparing Caesar’s ambition to a ladder that, if he is allowed to reach the top, may cause him to become too proud and scorn the very people who elevated him to such a lofty position.  

And therefore think him as a serpent’s egg—
Which, hatched, would as his kind grow mischievous—
And kill him in the shell. (2.1.32–34)

In this simile, Brutus again rationalizes killing Caesar before he has a chance to abuse his power, comparing him to the egg of a poisonous snake that must be crushed before it hatches. 

Act III

But I am constant as the northern star,
Of whose true-fixed and resting quality
There is no fellow in the firmament.
The skies are painted with unnumbered sparks.
They are all fire and every one doth shine,
But there’s but one in all doth hold his place.
So in the world. 'Tis furnished well with men,
And men are flesh and blood, and apprehensive,
Yet in the number I do know but one
That unassailable holds on his rank,
Unshaked of motion. (3.1.65–75)

In this extended simile, Caesar boasts of his self-assurance by comparing himself to the North Star, the only star in the sky that remains fixed in its position throughout the night; in contrast, he dismisses all other men as apprehensive, or self-doubting, likening them to the countless other stars that continually shift their position. 

Pardon me, Julius! Here wast thou bayed, brave hart;
Here didst thou fall; and here thy hunters stand,
Signed in thy spoil, and crimsoned in thy lethe.
O world, thou wast the forest to this hart,
And this indeed, O world, the heart of thee.
How like a deer, strucken by many princes,
Dost thou here lie! (3.1.215–221)

In this extended metaphor, Antony compares Caesar, just after his assassination, to a hart (deer), over whose bloody body the hunters (the conspirators) are still standing; Antony exults the fallen deer (Caesar) by saying that the whole world was his forest, while at the same time flattering the conspirators (and avoiding their anger) by calling them princes. 

Act V

Now is that noble vessel full of grief,
That it runs over even at his eyes. (5.5.17–18)

In these lines, Brutus’s friend Clitus compares the weeping Brutus to a container overflowing with grief; a few moments before, Brutus had asked Clitus to kill him, knowing that his army was on the brink of defeat. 

Villains, you did not so when your vile daggers
Hacked one another in the sides of Caesar.
You showed your teeth like apes, and fawned like hounds,
And bowed like bondmen, kissing Caesar’s feet,
Whilst damnèd Casca, like a cur, behind
Struck Caesar on the neck. O you flatterers! (5.1.40–45)

In these lines, Antony uses a string of similes to mock the conspirators for the cowardly way they killed Caesar; most of them, he says, feigned servility, smiling and kissing Caesar’s feet like submissive animals (apes and hounds) or slaves (bondmen); meanwhile, Casca snuck up behind the distracted Caesar like a cur (a mutt) to strike the first blow.