Unknown to the Federation at this time.
The Yoomutat of the planet Kivus have developed distinctive survival mechanisms over the course of their evolution. Living in a hostile environment, they have gained the ability of autotomy (losing and regrowing) for their limbs as well as for a very specialized stinging apparatus located at the base of their cervical vertebrae. The stingers retract along the spinal canal until needed.
When threatened, the Yoomutat can extend the stinger out through stomas, one on each side of their necks, in a whip-like manner. Depending on the height of the individual Yoomutat, the stinger can extend out from 2-3 feet in front of them. Each extension has a stinger, which embeds in the skin of the victim due to tiny, almost microscopic barbs, tearing it clean from the extension and making it hard to remove. The Yoomutat will regrow a new stinger over the course of a few days. The stinger has its own ganglion that keeps the musculature of the sting shafts moving (thus embedding the sting deeper) and the venom sac pumping for several minutes after it detaches.
Culturally, they are a fearful society, not trusting strangers and quick to attack.