Gloworms are floating segmented glowing worms, They glow with a silvery light when illuminated, but are dull grey when they turn the light off. They are banded like a terrestrial earthworm. but have no recognizable features.
Their homeworld is unknown and very little is known about them. It is also not known how they spred aroudn the universe. Maybe in an earlier epoch as the Verms or the Riders or maybe picked up by an unfortunate explorer.
They are solitary creatures and feeds on the life energies of other living creatures and do prefer sentient beings. They are a kind of predators. They have hypnotic powers that they use to take control of their victims before feeding on them.
Source: GURPS Aliens