What is the right word for bloodthirsty dictator?

According to Reuters this,

"Mugabe, sole ruler since Zimbabwe's independence from Britain in 1980, is accused by his opponents and critics of running down one of Africa's most promising economies through a series of controversial policies, including the land seizures.

His critics say the 80-year-old Zimbabwean leader has become repressive in the face growing opposition to his rule, and has been forced to use violence and to rig elections held in the last five years to hang onto power.

Mugabe, a former guerrilla leader, denies the charges and in turn blames domestic and Western opponents of trying to oust him because of his black nationalistic programmes."