Final answer:
Some of Pizarro's men called him a butcher because of his brutal treatment and massacres during the Spanish conquest of Peru.
Step-by-step explanation:
Some of Pizarro's men called him a butcher most likely because of his brutal treatment and massacre of the Inca people during the Spanish conquest of Peru. Pizarro and his men committed numerous acts of violence, such as killing innocent civilians, looting temples, and destroying cultural artifacts.
For example, in the Siege of Cuzco, Pizarro's forces slaughtered thousands of Inca soldiers and civilians. Pizarro also ordered the execution of the Inca emperor, Atahualpa, despite his promise to spare his life in exchange for a ransom.
These actions earned Pizarro the reputation of being a butcher among his own men and the native people.
Learn more about Pizarro's brutality during the Spanish conquest of Peru