Idi Amin Dada
The former dictatorial leader of Uganda from 1971-1979, Idi Amin has been called "One of the most batshyt loco leaders ever to seize control of a chaotic African nation." (Actually, we call him that, but he's been called much worse.)
Other dictators might find their enemies to be targets, threats, or terror: Amin found them tasty: "After his coup of his predecessor, Apollo Milton Obote, Amin rounded up the military leaders that did not support his coup, murdered them, decapitated them and sat their disembodied heads around the presidential dining table, scolding them for not supporting him, and taking bites of their flesh."
Wracked by sexual diseases, almost totally illiterate (unable to write and barely able to read), and prone to marrying and divorcing multiple wives, Amin was not what one would call the most stabilizing force for the war-torn Uganda. However, as they were thrown into one small war to the next, the citizens could at least take heart that their leader was so many ants short of a picnic that he'd probably never turn on his own people... until he did. At one point, he gave all Asians in Uganda 90 days to leave, sans their businesses of course. Similar attacks against Christians, his wives' lovers and his own cabinet ensured that nobody came to him asking for advice on matters of the heart.
Of course, the most astounding fact about Amin is that after years of torture, military insurgency, mismanagement of Uganda's economy to the point of disaster, and deaths of over 300,000 of his own citizens, he was never incarcerated. He lived for years in exile in Saudi Arabia, where one newspaper reported that he ate "40 oranges a day" to keep up his "sex power".
Dada died in 2003, and is survived by four wives and 45 children.
The Most Evil Men in History: Idi Amin - YouTube