Little is known about Edward Zentner's past before he became a paranormal. After gaining his paranormality in the so-called White Event he became one of the first paranormals to admit themselves to the Clinic for Paranormal Research set up by Philip Nolan Voigt in Wisconsin. Zentner was placed in Therapy Group A along with Geraldine Rumlow and Leland Sharp.
At some point the three members of Therapy Group A began working as 'headhunters' for the Clinic, responsible for capturing escapees from the Clinic as well as other undefined duties. When one of the other therapy groups, Therapy Group C, otherwise known as the DP7, got wind of Voigt's plans for the paranormals in the Clinic, they escaped, and Zentner and his two colleagues were the first headhunters to be sent after them.
The headhunters soon encountered the escapees near the trailer park home of one of them, Dave Landers. Hiding in woodland, the hunters got the drop on the escapees and soon shot most of them with tranquilizer darts. Thanks to luck and their paranormalities, some of the escapees avoided or recovered from the tranquilizers, and fought the hunters up close. The speedster Jeff Walters disarmed Zentner, while Stephanie Harrington fought him. Although she managed to kick him, despite her superhuman strength, Harrington was defeated by Zentner's superior fighting ability. Later in the fight, with his two colleagues knocked out, Zentner held a knife to the unconscious Lenore Fenzl's throat to prevent Walters and Charlotte Beck from approaching. However, Beck used her power over friction to make him lose his grip on the knife, and the Antibody of Randy O'Brien knocked him out. The escapees left the three hunters tied up and sedated. 
However, the hunters later tried to apprehend the escapees again by posing as three police officers in a squad car pursuing them down a highway. Realizing the officers were the hunters, Beck used her paranormality to cause them to lose control of their car, which crashed. Randy sent his antibody to pull them out of the wreck and check their vital signs. 
Zentner was not seen for some time, until after the existence of paranormals became known to the general public and male paranormals were drafted into the army. Zentner had apparently joined up early on in this process, as he was made a Major. When most of the male members of Therapy Group C were drafted, Zentner gave them a hard time in training. 
When Dave Landers was being psychologically assessed by the paranormal Lieutenant Keith Remsen, Remsen saw Harrington and her paranormal healing power in Landers' dreams. He told Zentner, and Zentner remembered Harrington and realized she would be invaluable to the army as a nurse. Zentner ordered Landers to accompany him to Harrington's hometown where he attempted to coerce Harrington to enlist (as female paranormals were exempt from the draft). When she refused, Zentner threatened to draft her husband instead. Landers, who was unrequitedly in love with Harrington, saw her distress and struck Zentner, knocking him out. He told Harrington to go on the run with her husband and children, which she did. Deciding to desert the army, knowing he would face punishment for striking an officer, Landers broke Zentner's nose, hoping it would affect Zentner's paranormal sense of smell. Apparently it did not, as Landers was soon tracked down, caught and put in military prison. 
Powers and Abilities
Zentner's paranormality gave him a superhumanly acute sense of smell. His sense of smell was advanced enough to enable him to track others by their scent, and to know if someone was paranormal or not by smell.
Zentner had army training, and also had a black belt in Tao Kwan Do, making him a good hand-to-hand fighter.
Normal human strength.
As a Clinic headhunter Zentner used hunting rifles loaded with tranquilizer darts. As an Army major, he was armed with conventional firearms.