When her 17-year-old sister Sondra committed suicide shortly after being assaulted by a pair of men, Marian Mercer vowed revenge on the men involved and the patriarchal society that left them unpunished. Taking the name Pagan, she trained her self to physical perfection and practiced martial arts. Once her preparation was complete, she hunted and kidnapped the men involved, each in turn, beating them nearly to death. In doing so, she attracted the attention of the Batman.
Pagan appeared most often under the pen of Alan Grant. First as an antagonist for Batman, she was later portrayed as a vigilante with Batman's begrudging respect.
After her initial encounter with Batman, Pagan was acquitted of the assault charges for attacking the men; the jury found her to be justified since the men had driven her sister to her death. Marian continues to keep her vow to protect the women of Gotham. She encounters Batman again after she is accosted by, and subsequently defeats, some street thugs. He is skeptical of her, but they agree to work together, as both are hunting a mysterious killer. This killer is later revealed to be one of the Bloodlines aliens, Gemir.
She is later shown as an aspect of a lucid dream Batman generates while under attack by the villain Narcosis. She fights along with Robin, Anarky, The Hood, Joe Public, and others as help Batman calls on to combat his drug induced nightmares.