|Alias(es)||Dr. Z / Mr. Z|
|Residence||Rubic City, Veelox|
|First appeared||The Reality Bug|
|Last appeared||The Reality Bug|
Dr. Zetlin, also Z, Mr. Z, or Dr. Z, was the creator of Lifelight. He lived on Veelox, and spent most of his adulthood in a Lifelight jump.
The Directors recognized young Zetlin's genius and took him away to be given special training that would maximize his intellect. He had an unhappy life because he never knew what it was like to live as a normal person. At an early age, it was believed that Saint Dane planted ideas in his head that would enable him to design the Lifelight computer, upsetting the social balance of Veelox.
When Zetlin created Lifelight, he sealed himself into an automated jump, without any other people involved to phade or vedd for him, and stayed there until the Reality Bug forced him to shut down the jump. In the jump, Zetlin lived in a strange building called the Barbican. The Barbican was filled with means of both keeping away intruders and allowing Zetlin to engage in challenging and thrilling sports competitions. The Barbican was surrounded by a dark, rainy city which Zetlin imagined to serve as a reminder to the life he never wanted to return to.
Upon learning of the Reality Bug and the way that Lifelight had set Veelox on a course for ruin, Zetlin left his jump and shut down Lifelight. Zetlin told the people of Veelox that the fantasies created by Lifelight were never meant to replace reality, and that Lifelight should be kept offline until the people of Veelox could find a balance. However, Saint Dane, who had assumed the form of the prime director Kree Sever, dismissed Dr. Zetlin's statements and restarted Lifelight, ensuring that Veelox would fall into chaos.