Kelpien

The Kelpiens are a alien species native to a region of space somewhere in the Alpha or Beta Quadrant. They are also members of the United Federation of Planets.

Physiology
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.

Culture
The Kelpiens were originally a prey species, used by another species as cattle and food. Due to their role their ancestors played the Kelpiens tend to be more cautious when faced with the unknown. Rather than confront a possible enemy or danger, Kelpiens would prefer to avoid it. This mentality has rather blemished their species as a race of cowards.

Source

 * Star Trek Discovery: The Vulcan Hello