Moya is a massive living ship, a Leviathan, a biomechanoid being, and one that has kept the crew safe for many cycles. She has a single defensive manoeuvre, the ability to starburst, jumping away from an area in space, and arriving in a new unpredictable place. She is later given a defence screen as well, in the episode PK Tech Girl, scavenged from the Zelbinion, but is still unprepared for the many battles she faces aginst the Peacekeepers, Scarren, and many others.

Moya's insides serve as all the necessary chambers for the crew. Docking bays, maintenance bays, command structures, corridors, quarters, all are present thanks to the clever breeding and engineering work in Leviathan history. Moya has a few little extras though, thanks to the Peacekeepers. In the episode The Way We Weren't we learn that a Peacekeeper project to grow a Leviathan gunship was started by Captain Crais. When the shield preventing this from happening is broken (in They've Got A Secret), Moya becomes pregnant.

Moya isn't able to spend much time with her baby, Talyn, thanks to the intervention of Crais, and finds guarding her child difficult. When Talyn is eventually lost in the episode Wolf In Sheep's Clothing, Moya is badly affected, but deals with her grief and goes on to continue helping her crew. She has grown close to those aboard, in particular Aeryn Sun, but also to all the other crew after their many adventures.

A key part of Moya is Pilot. Actually a seperate entity, the two are bonded together for life, with the kind of symbiosis unseen on Earth. Pilot is able to guide and control Moya, allowing the crew to exist abaord Moya, thanks to careful monitoring of life support, temperature, etc... Without Moya, Pilot would not leave his home planet, and without Pilot, Moya would exist as a wild ship with no control, and no ability to help her crew. The two are the closest partnership in the series (even closer than Aeryn and Crichton!), and they are always there to help save the day.