Beings of energy living within the ion storms of Hetemit IX, believed to be the remains of the Illyrian colonists who vanished there, encountered by Pike and Spock in Ghosts of Illyria.
The ion storm lifeforms are glowing, bodiless beings that move within the violent storms sweeping Hetemit IX. They appear to be what became of the planet's Illyrian colonists, whose consciousness was somehow absorbed into the storms.
They appear in the Strange New Worlds episode Ghosts of Illyria in 2259. An Enterprise landing party is studying the deserted colony when a storm closes in, stranding Christopher Pike and Spock in the library. Shapes batter at the doors, and the two officers assume they are under attack.
When the storm finally breaks into the building, the beings instead surround the pair and shield them from it. Spock's reading of the colony's records suggests that the colonists had tried to reverse their genetic modifications in the hope of joining the Federation.