Tunnel Builder

The tunnel builders are a presumably extinct civilization responsible for the creation of an intricate network of tunnels present on numerous planets, many of which are currently uninhabited.

Nothing is known about the tunnel builders, except for some images carved on bottles and other artifacts found in archaeological ruins. The images represent the tunnel builders as bipeds, with blob-like heads, featureless except for sensorial antennae, and a bushy tail.

Their relationship with the Slugs is unknown, but they don't seem to be the same species.

Appearances

 * Shakespeare's Planet, by Clifford D. Simak (1976)