Infiltration Unit Zeta Zeta is a synthoid who was originally designed to gather information and kill select targets for the NSA. However, after realizing that one of his targets was actually innocent, he refused to kill anymore and went on the run. Ever since, Zeta's creators have been pursuing him, convinced that he was reprogrammed by terrorists. Zeta hopes that his creator, Dr. Selig, can prove his innocence, and so is searching for him. He meets Rosalie after saving her from a street gang, and in return she helps him escape from the agents pursuing him. Though Zeta no longer possesses most weapons he was originally equipped with, his arms are equipped with saw blades and cutting lasers; he also possesses various non-lethal tools, such as welding lasers, a computer interface, and an unlimited credit card. He has a high-endurance metal frame and the ability to project a hologram around himself and alter his voice. Additionally, he is faster than a human, can perceive wavelengths outside human perception, and is self-repairing to a limited degree.
Rosalie "Ro" Rowan Rosalie Rowan is a 15-year-old girl who grew up in foster care in Hillsburg with Sheriff Morgan and his family before being assigned to a state-run home on Gaines Street. The only thing she knows about her family is vague memories of an older brother, who she was separated from years ago by the foster care system. She ran away from the state system at fifteen years old and joined a gang to have a home. But when she refused to take part in robbing a bank to prove herself to the leader, she left the gang. As she and Zeta search for his creator, Ro embarks on her own journey as she searches for a "family" to belong to. She serves as Zeta's guide to "passing" among humans, and teaches him lessons about being human. Additionally, she is a source of comedy in the series, contrasting with Zeta's stoic nature. She is visually inspired by Pris from
Blade Runner.
Agent Orin West and Marcia Lee Formerly Scout Unit Four, partner NSA Agent Orin West and Marcia Lee fail to capture Zeta at the Wood Valley Maryland hoverbus station and are assigned to work for Agent Bennet as punishment, dedicating themselves to capturing Zeta. West is clumsy and overeager, while Lee is more controlled and by-the-book and keeps him in check. Lee has her doubts about Zeta's guilt and is willing to believe he might be peaceful, which sometimes putting her at odds with Bennet. Lee eventually leaves Bennet's team and is replaced by Agent Rush. West shares a last name with and resembles
Wally West, who is also voiced by Rosenbaum. However, showrunner Bob Goodman has stated this was coincidental.
Infiltration Unit 7 IU7 is the next generation of Infiltration Unit after Zeta, which Agent Bennet unleashes to capture its predecessor. Like him, it is a synthoid with mimicry skills and wields a large arsenal of weapons, but its metal frame is larger, powerful, and heavily armed. Because of the single-mindedness of IU7's programming, Zeta and Ro usually find ways to outsmart it. ==Voice cast==