Lumen

The Lumens were a species of grubs native to the Green Planet.

Biology
A Lumen resembled a large phosphorescent grub. Its species were perfectly domesticated by the Asogians. Lumens lived on the walls of the Chemon Xrus, dining on the minute organisms which produced the light to homes.

Appearance

 * E.T.: The Book of the Green Planet by William Kotzwinkle and Steven Spielberg