Line creepers were organisms similar to conduit worms that lived in the Unknown Regions. They were segmented, slender worms that could grow to be as long as a Chiss. They would chew into power and navigation cables and live on the electrical energy. They left a tell-tale amount of signature gas behind, and could not live in a vacuum.
By 22 ABY, the Chiss had unsuccessfully tried for years to exterminate them.