Vaikan were generally small and scrawny with large, long ears and large eyes. They had a short, nearly flat snout, and rows of short, sharp teeth in their mouth. Vaikan had four fingers including an opposable thumb as well as three toes. From their fingers, they could discharge jolts of electricity.
Having to adapt to the heavy radiation from their star, they evolved to have skin that varied in shades of blue. Not only could they survive this radiation, but they also metabolized it using special cells in their skin. Their large ears primarily fulfilled this function. Their ability to photosynthesize reduced their overall caloric needs which allowed them to adapt to their original desert environment.
Vaikan also had supplementary fins that could retract and extend. These fins also served as means of gathering solar energy. Overtime, these fins shrunk during their long time spent in spacefaring environments.
Males and females were not visibly distinguishable until hitting puberty around age ten. Males tended to grow taller and acquired more muscle mass while females tended to be smaller with more body fat. In addition, females also had mammary glands which were used to nurse their hatchlings.
Vaikan had binocular eyes that allowed for depth perception and stereoscopic vision; eye color often varied between blue, purple, orange and red. Both eyes were large and oval-shaped, being taller than they were wide. They had two sets of eyelids - the outer ones blinked horizontally, and the inner ones blinked vertically. Although they lacked trichromatic vision, they could see deeply into the ultraviolet spectrum. As such, they perceived their surroundings in shades of blue and purple with amounts of vibrancy and brightness denoting subtle color transitions.
Vaikan, as well as other species native to Ucharpli, had a unique brain chemistry with their own set of hormones. Because of this different chemistry, adrenaline from an outside source could induce powerful hallucinatory effects. For much of Vaikan history, adrenaline was considered an illicit drug.
Vaikan also required a four-week hibernation period once every two standard years. During this time, they would enter a deep state of sleep and experience lucid, vivid dreams. In some cultures, it was common practice to write down the events of these dreams often to interpret for self-reflection or as prophecies for the next two standard years to come.
Vaikan have the ability to discharge electricity from their fingertips. Running down from their brain to their arms was a series of electrical cells. Upon activation via a brain signal, a reversal of charges occurred in the air. This shock could send enough volts upon the target to stun them for a few moments. An organ dedicated to holding electrical charges existed near their two hearts and sternum which could be charged through a combination of both caloric intake and periods of sleep.
The stun mechanism was an evolutionary leftover from their more primitive ancestors who used electric shocks to ward off their enemies. When Vaikan evolved to become predatory creatures, they learned how to use their electrical abilities in conjunction with weapons such as copper spears.
A Vaikan's snout contained an olfactory blub. Vaikan also had a trachea that connected their mouth to their lungs. As a result, their mouths functioned for both consumption of food and for breathing.
To adapt to the lower oxygen levels, Vaikan had two hearts to be able to cycle oxygen throughout the body very quickly as well as two large lungs. Additionally, the openings in their arteries were considerably wide allowing. The presence of two hearts in the Vaikan body was the source of the name of the Twin Hearts Nebula.
Vaikan metabolized most often from their ability to absorb UV radiation. However, in order to survive cave environments as well as Ucharpli's lengthy periods of nighttime, they needed to directly be able to ingest food as well. Due to most of Ucharpli's life evolving thick carapaces, it became a necessary adaptation to swallow small pebbles to aid in digestion. Vaikan lacked a direct, conventional equivalent to a stomach, as their primary digestive organ could better be described as a gizzard which was particularly muscular and could grind up food. They also had a secondary organ comparable to a crop which could store food before it was ready for digestion. It could also expand, which was crucial for preparation of their four-week hibernation every two years.
Once enough nutrients had been extracted, uric acid was excreted through their cloaca as a means of conserving water and removing toxins from the body.
The Vaikan skeleton had a high concentration of metals much like the bones of other Ucharpli-native animals. Part of a Vaikan's diet consisted of small stones as well as the bones of other animals which lent to the absorption of microscopic metallic particles throughout the body. These bones also served as conduits from which electrical signals could be sent throughout the body.
Vaikan naturally lived to approximately 160 standard years. Although Vaikan possessed object permanence upon hatching, they had an otherwise fairly slow aging process when it came to cognitive development. They did not gain the ability to self-recognize until age ten standard years. Males and females looked nearly identical until puberty. The main reliable way to tell young Vaikan apart from one another was their size. Males would on average grow much taller and develop much larger ears and solar fins.
After approximately age 20, their sexual dimorphism would become much more prominent. The development process would last approximately ten standard years, during which time, their hormonal growth would accelerate. The development process would last until approximately age thirty. As such, across many Vaikan societies, age of consent ranged from age 25 and 30.
Upon sexual maturity, their brains became fully developed, and they gained better control over their emotions and become more adept at solving mathematical and logical problems.
Vaikan were monotremes - both males and females used their cloaca for reproduction. After conception, a soft-shelled egg would develop inside the female and would be laid after seven months. Hatching would take approximately one month, and the hatchling would break open the egg from the inside via an egg tooth. The mother would then nurse the hatchling with milk.