Zev was raised in a Holocare Home as a candidate for the Wife Bank. Unfortunately she was overweight and unattractive, and this fact was made very clear to her throughout her life. Her future did not look good. During the Lifting Of The Veil ceremony she was charged with "humiliating her husband in the temple and failing to perform her wifely duties.
She punched the twelve year old groom out cold after he insulted her. Zev was sentenced to be transformed into a Love Slave who would automatically fall in love with whoever she saw first (intended to be a selected cleric).   However, the transformation process was only half completed.
Although she was physically moulded into the ultimate female form, she retained her own personality, including the bitterness which had evolved from others' treatment of her.  She now had the chance to experience what life was like from both ends of the looks spectrum.
She was also accidentally spliced with some Cluster Lizard DNA, resulting in special abilities including the power to communicate with these creatures.
The new Xev was created from the protein remains of the original Zev.  She was brought back to life by the alien plant lifeform called Lyekka as a gift to Stanley Tweedle.
She is still part Cluster Lizard, but Lyekka also used the protein from EJ Boss, a farmer and space explorer from Potatoho, to reconstruct her.
Xev's physical appearance differs from the original Zev as Lyekka only had 790's vague description of her to use as a template.  She seems to be a lot less innocent than Zev, and she still has an accelerated libido.