Tranthellix was a planet in the Tranthellix system, located in the Tangles of the Senex sector in the Mid Rim. The rugged, mountainous planet was controlled by the Human noble family House Petro. Like many worlds in the Senex-Juvex, House Petro had conquered the planet's native species and consigned them to slavery.
Tranthellix was the homeworld of the flying, predatory Tranthebar Mountain rippers. Profiting from young Senex-Juvex nobles looking to become involved in ripper racing, House Petro refused to export the Mountain rippers, but many were captured by the planet's populace and smuggled offworld for illegal races.
- Galladinium's Fantastic Technology (First mentioned)
- The Essential Guide to Vehicles and Vessels
- The Essential Atlas