At this stage of The Tragedy of Julius Caesar the triumvirate is attempting to consolidate and organize their power in order to plan a campaign against Cassius and Brutus. They immediately begin totalk about who should live and who should die.
In this scene, Antony and Octavius are discussing Lepidus. Antony does not feel that Lepidus is worthy of an equal place in the triumvirate, so he makes several unflattering comparisons. When he says of Lepidus, “He shall but bear them [slanderous loads] as the ass bears gold,” he is comparing Lepidus to a donkey. This is a simile, because he is using the connective word “as” to make the comparison. He is trying to say that Lepidus is useful for work in the same way a donkey is.
When Octavius says that Lepidus is a “a tried and valiant soldier,” Antony counters with “So is my horse.” He’s making the point that you don’t have to be very intelligent to be a good soldier. This is similar to an implied metaphor. He didn’t come right out and say that Lepidus is a horse, but implied it. The reader gets Antony’s meaning without a direct comparison.
The bear comparison is also an implied metaphor, because they don’t actually use the word bear, saying only, “we are at the stake, And bay'd about with many enemies.” It is left up to the reader to assume that the “we” is a meant to be an animal, possibly a bear.