Morrok
From Memory Alpha, the free Star Trek reference.
The morrok is a monster in Drayan folklore, that is said to come at night and take people when they die.
In 2372, a group of elderly Drayans on the crysata moon, whose attendants had died in an accident, told Tuvok that the morrok was responsible for the disappearances of several of their number. In fact, they were dying of natural causes. (VOY: "Innocence")
