Homeworld: unknown. Vortigaunt were part of the workforce of the Nihilanth organism when he fled his world to retreat on an artificial complex of asteroids called Xen near an unknown nebula in a unknown region of space that is believed to be in a universe adjacent to our own. Wether or not they are from our universe remains unknown.
Vortigaunts are very intelligent and social humanoids creatures. Having being under the rule of the Nihilanth for an unknown lenght, it is unknown what their oriignal evel of development might have been. On Xen, they are shown to have been used as factory workers and drones . Despite this, they have developed an intellectual culture, valuing poetry, music and philosophy, and also practised the husbandry of antlions, large insects that live in underground hives, as an ancestral tradition. The Vortigaunts believe in a binding life-force referred to as the "Vortessence", which they believe is the fabric of the universe, made of vortal cords, of which everything is woven . The Vortigaunts are able to read and control this force for their electrical powers, nearly hive-mind telepathy and, likely, their ability to take power from objects. They are also able to use the Vortessence to heal wound to an extent and keep the dying from passing on. They can use their powers coupled with "the extract" of Antlion larvae to bring the nearly dead back to life.
Vortigaunts possess their own method of vocal communication, "flux shifting". This method of communication involves both speakers vocalising at the same time and cannot be understood by other species who lack the auditory anatomy to interpret the sounds. In addition to standard conversation, flux shifting can be used by Vortigaunts to communicate over long distances.
In appearance, a Vortigaunt is a somewhat humanoid figure with two legs and two arms, but has an additional arm protruding from its thorax. Vortigaunts possess digitigrade legs, allowing them to move quickly. In addition, Vortigaunts have mottled green-brown skin, sharp teeth and clawed hands. Vortigaunts have a slightly hunched posture, and their faces are dominated by a large red eye. In Half-Life, this eye is surrounded by three to five smaller eyes. Vortigaunts are shown to possess strong nasal senses. Vortigaunts are not typically seen wearing clothing. Vortigaunts are depicted as meat eaters, but are believed to be omnivores.