High Quality Content by WIKIPEDIA articles! Vulcans are a humanoid species in the fictional Star Trek universe who evolved on the planet Vulcan, and are noted for their attempt to live by reason and logic with no interference from emotion. They were the first extraterrestrial species to officially make first contact with Humans, and later became one of the founding members of the United Federation of Planets. Vulcans are featured in all five Star Trek series, three of which featured a Vulcan as a main character. Vulcans are depicted as similar in appearance to humans. The main physical differences are their eyebrows and ears: the former are arched and upswept, while the latter feature pinnae which taper into a point at the top. Vulcans can be classified into various races. Most caucasianoid-like Vulcans typically appear with a subtle greenish hue to their skin, due to Vulcans' copper-based blood.