Races of Warhammer 40k
Orks
A race from Warhammer 40k. Also known as 'Greenskins'. They have a Warhammer Fantasy equivalent, only major differences being the more common spelling of orc with a 'c' instead of a 'k', and a lower level of technology, related to the setting.
Orks could be considered one of the more successful races of the 41st millenium. Despite their entire lack of structured education or training, they seem to be very proficient with all kinds of technology, which they inevitably utilize for their armaments (of which firearms and vehicles are the most common). They are often very resourceful, able to have the minor greenskins, such as 'Grotz' (goblins), construct several working vehicles and machines out of mere scrap. A large contributing factor in the orks' success is their ability to breed extremely fast because of their fungal like existence. This means that an ork will spread several spores in his life time, each of which is able to grow into another ork, given enough time. Orks as such breed through asexual reproduction. The fungal physiology of the ork is also why they are so tough as they are, since their body has fewer vital organs.
Common ork weapons are a choppa and a slugga.
Orks are commonly believed to be stupid and superstitious by the other races of the 40k world.
Tyranids
OMNOMNOMNOMNOMNOMNOM Delicious Biomass, you must devour it.
"Tyranids" are extragalactic beings in Warhammer 40k that exist only to eat living things. They have been expected to arrive on Terra's doorstep anyday now for years, being stalled by a force even more malicious then they are: GW's reluctance to move the story forward. Fa/tg/uys masturbate furiously to anthropomorphized versions of tyranids.
Tau
The Tau are a playable race in Warhammer 40k. When first discovered by humanity, the Tau were a barbaric and primitive people. Then their planet was trapped in a warp storm for a few thousand years and they emerged from the other side as a unified species, led by the mysterious Ethereal caste and devoted to the concept of the "Greater Good". The Tau were originally developed because Games Workshop felt their setting needed an optimistic race, making the Tau the least grimdark faction in the game. Recent fluff has them gleefully arbitrarily sterilising humans that come under the rule of the Tau Empire, and it says something about 40k that despite this they're still the friendliest race in the setting.
They are a technologically advanced race, and have some of the most powerful ranged weaponry in the game. Tau units in general are rather weak in close combat, so they rely on alien auxiliaries such as the Kroot and Vespids who have joined the Tau Empire to bolster their strengths in this area. Fire Warrior veterans and commanders go to war wearing advanced battlesuits, allowing them to field even more firepower.
Tau unit designs were somewhat inspired by Asian culture and Japanese mecha. As a result, /tg/ declares the Tau are weeaboo. Their devotion to the philosophy of the Greater Good often leads to them being labelled as communists, too.
Notable Tau
Eldar
Eldar are la dee da space elves.
Dark Eldar
The INTERSTELLAR ROCKSTAR version of the eldar, which also happens to be their polar opposite. The dark eldar are a race of awesome space elves who fly around the galaxy killing, fucking and tourturing anything sentient.