Klingons

Klingons are a humanoid race of warriors, characterized by dark skin, distinctive forehead ridges, and a bad temper. Some, however, possess a more level-headed temperament as well as a smooth forehead in place of ridges; this was apparently due to a virus that had spread among Klingons at some point, the virus altering them in both a mental and physical capacity. They don't like to talk about it with outsiders, though.

The Klingon homeworld is called Qo'noS, but being that they're a society of warriors, they've conquered numerous planets within the galaxy, forming the Klingon Empire. Despite being bloodthirsty warriors, though, Klingons greatly value honor, as well as tradition and ritual. They also greatly revere a leader from ages past, Kahless the Unforgettable, considered the first Klingon warrior and an almost spiritual figure.

Notable Klingons

Chancellor Gorkon Star Trek VI	General Chang Star Trek VI	Colonel Worf Star Trek VI
Worf DS9	Alexander TNG	Kurn TNG
K'Ehleyr TNG	Gowron TNG	General Martok DS9
Duras TNG	Lursa TNG	B'Etor TNG
Toral TNG	B'Elanna Torres Voyager