Agent Singer of the NID worked undercover in the town of Steveston, Oregon, posing as the barkeeper in Crusty Bill's Bar. Cloned symbiotes had taken hosts among the townspeople, creating "nightwalkers", and Singer and his partner, Agent Cross, had been monitoring the situation for three months as part of an official NID operation. When Singer became a nightwalker, he betrayed Cross and implanted him with a symbiote as well. They were charged with taking the symbiotes to NID headquarters to implant the entire organization, but they were stopped by SG-1's investigation before they could complete the mission. All the nightwalkers responded to treatment with an antibiotic, and the hosts recovered when the symbiotes were destroyed.
Portrayed by: Sean Tyson
Episode Reference: Nightwalkers