Nucleogenic Cloud Being
History:
Nebula-like life-form native to the Delta Quadrant of the galaxy. The Starship Voyager encountered
an individual of this species in 2371, accidentally anflicting serious harm to the creature by entering its body to harvest omicron
particles. The nucleogenic cloud being was over seven AUs in diameter and as composed mostly of hydrogen, helium, and hydroxyl
radicals. The crew of the Voyager was eventually able to help heal the creature.
VOY "The Cloud" ; Star Trek Encyclopedia II
.