Tyrant

A tyrant was the absolute ruler of a political entity or specific area who ruled without constraints and oppressive towards his subjects.

In Klingon mythology, Molor was sometimes described as a tyrant. 

The 19th century song A British Tar featured the line "...or the tang of a tyrant tongue!"

In the novel Commodore Hornblower, Napoléon Bonaparte was referred to as the "Corsican tyrant" by the parson of the village of Smallbridge. 

During the Eugenics Wars on Earth in the 1990s, a series of Augment tyrants ruled over several areas. Khan Noonien Singh was described as "the best of the tyrants" and was the last one to be overthrown. 

On Sarpeidon, Zor Kahn had the epithet "the Tyrant". 

In 2370, Kubus Oak claimed he had never liked the "arrogant tyrant" Gul Dukat, even though the two had worked closely together during the occupation of Bajor. 

In 2372, $𝜇$ described $𝜇$ as a "vile little tyrant".