Loomis was a 21st century Human who was recruited by the Xindi-Reptilians in 2004 as part of their effort to create a bio-weapon with which to destroy Humanity.
As an employee at a blood bank in Detroit, Michigan, Loomis was recruited for his access to clients of all blood types, as well as his willingness to kidnap these people for money. Loomis agreed to supply the Reptilians, who had covertly traveled back in time from the year 2153, with victims of each blood type, allowing the Reptilians to augment their bio-weapon to maximize its lethal effect. Loomis was unaware of the true nature of his employers, at one point considering the idea that they were terrorists, although he did not allow this to deter him from continuing to accepting money for his illicit activities.
When he was attempting to kidnap Lawrence Strode, he referred to his supervisor at the blood bank as "the fat broad" that paid him.
Before Loomis had a chance to abduct the seventh person, he was taken prisoner by Starfleet Captain Jonathan Archer and his first officer T'Pol, who had also been transported back in time by 31st century temporal agent Daniels. Believing Archer and T'Pol to be law enforcement agents, Loomis initially refused to cooperate without a lawyer, but was convinced by Archer, who had demonstrated his willingness to use physical force to obtain Loomis' assistance. T'Pol, for her part, regarded Loomis with thinly veiled disgust. Loomis subsequently took Archer to the secret location where the Reptilians were conducting their experiments, telling them that Archer was the seventh victim, allowing Archer access to the Reptilians' experiments. As Archer attempted to gather intelligence, Loomis stayed with T'Pol who did not bother to conceal her distaste for him. T'Pol was eventually forced to stun him with her phase-pistol to prevent him from warning the Reptilians. Archer and T'Pol were eventually successful in their efforts to halt the Reptilians' experiments and, before returning to their own time, placed an anonymous call to the police, informing them of Loomis' activities and the people he had abducted. Loomis was taken into custody by police officers, who dismissed his claims of having witnessed "lizard people" and "ray guns" as the effects of drug abuse. (ENT: "Carpenter Street")
Loomis was played by Leland Orser.
In the final draft script of "Carpenter Street", Loomis was described as "a wiry, nervous-looking man in his 30's". He was to have been introduced walking "briskly" down a sidewalk. However, in the final edit of "Carpenter Street", he is initially shown pulling up to the sidewalk in his car. In ultimately omitted dialogue from the same script, Loomis admitted to having had, during his childhood, a ray gun that looked much like a Starfleet phase-pistol.