The LEXX is a bioengineered, Manhattan-sized, planet-destroying, living spacecraft central to the Lexx science-fiction TV franchise. It has the shape of a giant wingless dragonfly. It was grown from organ collections used on the Cluster, the seat of the Divine Order. Its original intent was for use by His Divine Shadow as a terror weapon to force the surrender of a group of "Heretic" worlds that had rebelled. It was only when Stanley H. Tweedle, Zev Bellringer, and Kai commandeered it to escape from the Cluster.

The Mechanics of the LEXX are quite simple. The 'key' is an intangible living thing that allows whoever is hosting it to captain the Lexx. Commands are carried out by voice of the captain, however on the bridge there is a hand beacon that appears to confirm something important, like destroying a planet.

The LEXX needs to eat constantly to stay alive and useful, and can land on a planet's surface to scoop up suitable organic foodstuffs. The moral dilemma of destroying inhabited worlds is a recurring plot theme.