Vulcans originated on the world known as Middle Earth, where they engaged in much feasting and destroying of jewelry. Although this sort of carrying on continued for many centuries, eventually the Vulcan government of Middle Earth was taken over by a tyrannical man named Ernie of Keebler, who forced the Vulcans into slavery, where they were made to bake cookies.
After a few centuries of such torment, a man by the name of Surak lead a revolt against Ernie, after which many migrated to the desert planet which they later named after their own species, Vulcan. Surak is often known as the "Father of Vulcan Cosmetology," for being the first to tweeze his eyebrows into the distinct upwards slant which most Vulcans now have.
Surak also founded the Vulcan Fashion Academy, where Vulcans could go to learn not only the finer points of designing snappy couture garments with scalloped hems, but also how to tweeze eyebrows so they always looked fabulously pointy, and how to cut bangs in a straight line.
While Vulcans outwardly appear almost identical to humans, their bodies are, in fact, 79% green jell-o. Despite the gelatinous construction of their musculature, Vulcans are freakishly strong and are one of the few species in the known universe able to cut down the mightiest tree in the forest with a herring.
At birth, baby Vulcans' brains are replaced with computers, which allows them to do instant mathematical calculations, store large amounts of data, and play Vulcan solitaire. This also explains the Vulcans' trademark stoicism, on account of the fact that they are usually too preoccupied with playing card games to expend the extra energy required to produce facial expressions, or to communicate with lesser beings, such as humans.
As with humans, Vulcans come in several different ethnicities which appear oddly similar to those found on Earth. An example of a Vulcan displaying similar features to the humans indigenous to the African continent is Mr. Tuvok, of Star Trek: Voyager fame.
Although Vulcans are remarkably long-lived, they are susceptible to viruses and glitches in their programming, though those can often be corrected through a procedure known as the Vulcan Mind Interface. One terminal condition is known as the Vulcan Blue Screen of Death.
Vulcans claim to reproduce sexually through a mating cycle called Pon Farr, better known as the Vulcan Space Crazies. This is not true. Vulcans actually reproduce asexually by budding, which is why they all look alike. However, Vulcans do occasionally get a kick out of pretending to have the Space Crazies, in order to freak out lesser beings.