PhysiologyEditProtoss are roughly 2-3 metres tall and have two glowing eyes, digitigrade legs, semi-permeable skin covered in scales, four digits on their hands (of which two are thumbs) and toes, broad chests and shoulders, and narrow waists with slim midsections. Extending back from the crown of the head, protoss have a bony crest. Beneath it, emerging from the back of the head, are the nerve cords, allowing them to access their racial psionic gestalt.
Protoss derive sustenance from light, capable of living off of moonlight (reflected sunlight), and can go without light for extended periods of time. What little water they need is absorbed through the skin. The Dark Templar modified themselves biologically and used other techniques to survive on the formerly lightless world of Shakuras.
Protoss hear and smell through their skin, and it is believed that their primary sense is sight. Protoss have a sense of smell sharp enough to identify other protoss and see very well at night. A protoss' skin color may change in response to changes in its emotions. They are bereft of mouths, noses, or visible ears and are without a sense of taste. They possess three hearts.
A protoss' average life expectancy is lengthy; the Dark Templar Raszagal, aged 1045, was considered old. Protoss under 300 years rarely have any significant political positions. Meanwhile, Artanis, a member of the Khalai who was 262 years old during the Brood War, is considered young, despite his powerful military position.
Protoss blood is blue or purple. As in humans, coloration is considered a sign of ethnicity, with each protoss tribe having a specific subtly differing hue or typical pattern of markings associated with it.
Protoss can communicate telepathically with each other. They can do so through "speaking", a method that transmits little or no emotional content. Using their nerve cords they can also communicate in a manner which enables them to sense each others' emotions, a key part of their psionic gestalt, the Khala. During the Aeon of Strife this ability had fallen into disuse, but was restored by the mystic Khas. Protoss who follow the Khala use both methods of communication. Dark Templar ritually sever their nerve cords, which prevents the emotional link.