sentients
"THE WORM"

"The closest I can describe it is to say it was like... something very high up looked down at me for a tiny moment, and then moved on." - Commander Susan Ivanova, 2260

PHYSIOLOGY
The Worm is an extradimensional entity whose only physical manifestation on our plane is a strand of green light 9.2 million miles long and 22,000 miles wide. Stellar-level sensors can measure its dimensions, but cannot determine annything else since it does not physically exist on our plane. The Worm is not composed of particles, but ghosts of particles. It has the ability to move across several light years in a matter of seconds.

PSI ABILITY
Any being in proximity (within 20 light years) is affected by the elemental  nature of the Worm. Its effect is particularly strong on telepaths. The presence of the Worm causes every being's deep seated fear of the Other (or unknown) to come to the fore with the intensity of the feeling depending on you near one is to it. These primal feelings cause a being to lash out at any difference with lethal, self-preserving force.

HISTORY
The Worm appeared near Babylon 5 in late January, 2260. It caused a significant  amount of damage and loss of life, before it disappeared as it passed through the station.

NOTES
The Worm's appearance disturbed even the Vorlon Kosh Neranek.