When Zev dies in season 2, her remains are kept onboard the Lexx. A part plant character named Lyekka consumes Zev's remains, then using the images from Stan's mind, "grows" a clone of Zev. Since Stan does not know every detail about Zev a perfectly identical replica cannot be made. Therefore the reanimated Zev is now called Xev. [It is still pronounced the same, just spelt differently] Xev has the same personality as Zev, and remembers everything that happened, however her appearance is slightly altered.