Who is Marcus Calpurnius Bibulus from Caesar's Women and what is their importance?

Marcus Calpurnius Bibulus was a wealthy plebeian and one of the boni. He loathed Caesar from the time they were children, when Caesar humiliated him and nicknamed him the "Flea." Marcus does everything he can to block Caesar's legislation and election to Pontifex Maximux. He opposes Caesar regardless of the issue and refuses to work alongside him. When he and Caesar are elected consuls, he invokes the customary tradition of watching the skies to stop Caesar from enacting any laws. His actions, however, backfire because Caesar's ally, Clodius, vetoes Bibulus's claim that Caesar's year of consulship should be voided.