Why does Cassius refer to Caesar as "Colossus"?

Cassius is making an allusion (literary reference) to the Colossus of Rhodes, a famous statue that was one of the Seven Wonders of the Ancient World. This allusion occurs during Cassius's famous discussion with Brutus during which Cassius states his case against Caesar and argues that Caesar has no more right to become king than any other nobleman. Cassius is speaking sarcastically about Caesar by comparing him to such an enormous and famous icon. What Cassius really means is that Caesar is no more important or capable than any of the Senators in Rome.