KLINGONS
Brutal, savage, war-hungry, but with a deep sense of honor, the Klingons are the best alien race showcased on Star Trek. First introduced as bitter enemies in TOS, they were perfect stand-ins for our Cold War rivals. Eventually, the Klingons were given a makeup upgrade and became strong but contentious allies for the Federation as seen in TNG and other shows. The spinoffs and the later Star Trek films presented another, prideful side to the aggressive aliens with their sagittal crested foreheads
First Appearance: "Errand of Mercy" Star Trek