Kelpien

The Kelpiens are a sapient, non-spacefaring civilization native to the planet Kaminar. They share their world with a spacefaring species known as the Ba'ul.

Biology
The Kelpiens are tall, lanky humanoids. One of their unique traits is the ability to sense danger. This sense usually manifests when their threat ganglia spay out and are exposed at the back of their heads. The reason they are hunted by the apex predators on their home world lies in their delicious flesh which is made ever sweeter by the endorphins released while they are afraid.

Kelpiens are taller than Humans, and despite their fragile appearance, are also considerably stronger. Their feet appear to be digitigrade, and they can achieve speeds of up to 80 km/h while running. Their senses are also far more acute than Human senses, particularly their hearing, although their eyesight is also well-developed, and allows them to see in the ultraviolet spectrum.

Vahar'ai is the name of the biological process which signals when an individual Kelpien is ready to be culled, or harvested, by the Ba'ul. It is signified by an inflammation of the threat ganglia, accompanied by extreme pain and debility. This state is believed by the Kelpiens to be fatal, hence the fact that they allow themselves to be killed by the Ba'ul in the Harvests, which make up part of the so-called Great Balance of their homeworld. In reality, it is a temporary condition that allows a Kelpien to shed their ganglia, lose their innate fear and develop a new sense of courage.

After passing through vahar'ai, Kelpiens develop new instincts and retractable keratin-based dart-shooters appear where their ganglia used to be. As it turns out, post-vahar'ai Kelpiens are actually predators, evolved to prey upon the Ba'ul.

Culture
On their homeworld, Kelpiens who haven't undergone vahar'ai are treated as a prey species, used by the Ba'ul as cattle and food. Due to the role they play in the natural ecology of their planet, these Kelpiens tend to be more cautious when faced with the unknown. Rather than confront a possible enemy or danger, they would prefer to avoid it. This mentality has rather blemished their species as a race of cowards.

The Kelpiens believe in the Great Balance which they share with the pinnacle species on their planet, the Ba'ul. When their Vahar'ai, or time of death of a Kelpien came the Kelpiens willingly allowed themselves to be harvested, unaware that the Ba'ul do this in order to prevent them from undergoing the ensuing transformation that turns the prey into the predator.

Appearances

 * Star Trek: Discovery (2017)
 * Star Trek: Short Treks (2018)