Daisy Brennan (Beth Riesgraf) is the main villainess from "Cobra," the penultimate episode of Perception's second season (airdate March 11, 2014). She is the girlfriend of Greg Palmer, who was believed to be an undercover CIA agent under the code name, Cobra.
As it turned out, Greg was lying about being with the CIA, but not only was Daisy oblivious to it, she became angry at her parents when they told her that Greg was a fraud. Daisy's parents hired Fred Kleinman, a private investigator, to find out the truth about Greg. In response, Daisy informed her parents that Kleinman was doing a report on Greg being a national hero, hoping that they would leave her and Greg alone. However, Daisy's claim led to her parents calling Kleinman, and he was not only further convinced that Greg was a liar, he was going to write about it.
Believing that Kleinman was a literal danger to Greg, Daisy confronted Kleinman and told him to drop the story, but when he wouldn't, she took out a gun and shot him to death. The villainess was later found in her apartment by Dr. Daniel Pierce and Kate Moretti, where she fired shots at them under the belief that she was in danger. Kate handcuffed Daisy and took her in, and it was after this that she talked about Greg and his work with the CIA, while stating that Greg would do anything to protect her. After Greg was revealed as a pathological liar, he later confessed to killing Kleinman, with Pierce getting the confession out of him. However, Pierce quickly realized that Greg was lying again and he was covering for the real killer: Daisy.
Pierce, Kate, and Donnie Ryan later met Daisy once again, with Kate stating that Greg confessed to the murder. Horrified and shocked by the news, Daisy confessed to killing Kleinman, stating that he was a threat to Greg and his work with the CIA. Pierce revealed to Daisy that Greg was a liar and that Kleinman was exposing him, while also telling her that she killed an innocent man. In response, the evil Daisy continued to believe her delusions that Greg was with the CIA and that she did the right thing in killing Kleinman, claiming that Greg would have been tortured and killed if Kleinman exposed him. Daisy was handcuffed and arrested for Kleinman's murder.