Horrible Salt Vampires, or M-113 creatures, were the unofficial nickname given to a now extinct sapient species which once inhabited planet M-113. This creature was notable for requiring extremely large quantities of salt, specifically sodium chloride, to live. It could remove salt directly through the skin of other beings using the sucker-like structures on its fingers, a process which usually resulted in the death of the victim. Also noteworthy were the creature's illusory shapeshifting abilities. Although it could not physically change its appearance, it could use telepathy to project an illusion into the minds of those around it, making it appear like any person it wants.
The horrible Salt Vampire was a humanoid being about 1.5 meters tall. It has brownish skin and long white and purple fur covering its whole body, except for its face and hands. Its yellowed eyes and the deep folds on its face gave it a distinctly sad appearance. It also had a tubular mouth equipped with sharp, needle-like teeth. The creature used this mouth for consuming salt and probably other food sources as well. However, it also had three long fingers on each hand, each finger sporting three suckers similar to those found on the tentacles of Earth's cephalopods. These suckers were used by the creature to extract salt directly through the skin of a living victim, which was usually killed in the process. The horrible Salt Vampire was amazingly strong, being able to easily defeat a Vulcan in a fight. However, the Vulcans' copper-based blood system lacks the kind of salt which the creature fed on, which is sodium chloride, the same salt consumed by Humans.
In spite of its beast-like appearance and behavior, the horrible Salt Vampire was actually a sapient and highly intelligent being. Its home planet, M-113, is currently a desolate desert world filled with ruins of an ancient civilization. Since the horrible Salt Vampire encountered by the USS Enterprise crew in 2266 was the last member of its species, it is likely that its psychopathic killing behavior may have been atypical, possibly driven by insanity caused by a long period of isolation and an urgent and horrible biological need for salt.