The Yuuzhan Vong—”Children of Yun-Yuuzhan“, also called the Chosen Race, known to the Chiss and Ferroans as the Far Outsiders, and sometimes incorrectly abbreviated to Vong (which implied that one was disowned by their family and their gods)—were a sentient species that nearly destroyed the New Republic, and were responsible for the deaths of nearly 365 trillion sentient beings during their invasion of the galaxy.
The Yuuzhan Vong and their Chazrach slaves were among the few alien species known to originate outside the galaxy (the only known others being the Silentium and the Abominor). A typical Yuuzhan Vong resembled a Human in form, though they were taller and heavier than the average Human and had less hair on their heads. The Yuuzhan Vong were religious zealots, who viewed mechanical technology as blasphemy. Their technological innovations were genetically engineered and purely organic. Additionally, the Yuuzhan Vong deeply respected pain to the point of masochism, and strove to improve their physical capabilities through organ grafting. Such grafting was a status symbol within Yuuzhan Vong society.
Perhaps most notably, the Yuuzhan Vong were unable to be sensed through the Force. This confounded the Jedi who first encountered the Yuuzhan Vong. However, they were susceptible to some Force based attacks.