Sliver-Slurper

Sliver-Slurpers are a race of tall, thin, greenish aliens that feed on waste and sewage left by other races.

Biology
They possess no arms, but do have large eyes on the top of their head, and their feet hold suction cups to feed on waste and similar materials. After feeding, a Sliver-Slurper can grow to colossal sizes, rounding out like a hot air balloon. They aren't aggressive towards other alien races, yet give off a foul-smelling odor. Despite their huge size after eating, they don't show any signs of strain.

Culture and society
Sliver-Slurpers have full control over gravitational functions; being able to simply "float" after feasting on sewage and waste to return to their spaceship. The spaceships have huge strange areas for food, much like giant tankers.

Appearances

 * A Field Guide to Aliens: Intergalactic Worrywarts, Bubblonauts, Sliver-Slurpers, and other Extraterrestrials, by Johan Olander (2010)