Final answer:
The mob's anger following Caesar's assassination stemmed from fear of political instability, perceived tyranny by Caesar, and the sudden loss of a leader who had enacted numerous reforms.
Step-by-step explanation:
The mob became so angry after Caesar's assassination due to a combination of factors. Caesar had amassed significant power and loyalty from his victories, creating a deep divide between those who supported his reforms and those who feared his level of control, particularly within the Senate. His power consolidation alarmed the aristocratic Senate, eroding their privileges and leading to the perception that he was a tyrant. After his assassination, the efforts by figures such as Marc Antony to expose the conspirators and to highlight Caesar's contributions further inflamed public sentiment. Outrage was also sparked by fears of political instability and the potential loss of the gains made under Caesar's leadership. All these factors contributed to the furious response from the populace.