Mazariyan was a Separatist fortress on Xagobah designed by the Techno Union. It was a living organism or collection of organisms that had the ability to heal. The creation of the Mazariyan Citadel involved bioengineering Xagobah's native lifeforms such as fungus which normally fed only on bacteria but after the genetic engineering of the malvil-tree; it led to the creation of a living structure that killed prey around it without feeding on them.
At the center of the creature was a large chamber that was shaped more like a cavern than a room. In this point were numerous circuits that were covered with banks of monitors as well as Xabar fungus in the region. Thrusting from the floor was a huge shapeless purple mass which pulsed and shuddered in a manner similar to a massive slime mold. In this location were dozens of tentacle-like tubes which pulsed with a darkly glowing violet liquid stream that moved into the walls. These veins rippled with deep red color from the walls and into the bioengineered nerve center and fed the organic construct. This represented the fact as to why many individuals that went into the Mazariyan never returned as it devoured them to feed itself. Boba Fett was one of the few to escape Mazariyan in 19 BBY.
The fortress was breached by the Galactic Republic during the Clone Wars, which resulted in the deaths of many Xamsters.
- The Complete Star Wars Encyclopedia