The character was brought back to mainstream continuity after the company-wide reboot in Batman & Robin Eternal, using the code name Orphan, previously used by her father, David Cain.

The character made her cinematic debut in the DC Extended Universe film Birds of Prey,[3] portrayed by Ella Jay Basco.

Cassandra Cain first appeared in Batman #567 (July 1999), written by Kelley Puckett and penciled by Damion Scott (who are generally credited with her invention).

After Bruce Wayne returns, it is revealed that Cassandra's disillusionment was a ruse, and that she had willingly handed over her Batgirl mantle to Stephanie because she was acting under her mentor's orders, and she is now working as a codename-less vigilante.

[13] February 4, 2020 was the debut of Cassandra Cain's first graphic novel, Shadow of the Batgirl, written by Sarah Kuhn and illustrated by Nicole Goux.

While seeking a perfect bodyguard for Ra's al Ghul, David Cain finds a potential mother when he sees Sandra Wu-San fighting her sister Carolyn in a martial arts tournament.

During the "No Man's Land" storyline, after Gotham is leveled by an earthquake and isolated, Cassandra Cain saves Commissioner Gordon's life and gains Bruce Wayne's approval, and, eventually, becomes the new Batgirl.

Cassandra beats Rose by playing on her emotions to leave her open for a critical strike, giving Deathstroke no choice but to get her medical attention.

During this time, Cassandra starts developing a friendship with Brenda, the woman who owns the local coffee shop, and even a very short-lived relationship with a boy named Zero.

Cassandra also goes undercover for Batman, as Kasumi, in the Justice League Elite, working under Sister Superior to track and eliminate metahuman threats to the population.

She works with the Batman's old fellow Justice League members Green Arrow and the Flash, and forms a bond with Coldcast, who is the first Leaguer to whom she reveals her identity.

As the JLA falls, the Elite, united by the spirit of the deceased Manitou Raven, free Vera and vanquish Black, although the team disbands after this last mission.

Later, Cassandra approaches Dodge, a wannabe superhero with teleportation powers, wanting him to steal a drug that gives humans metahuman strength in exchange for money.

Soon after, Cyborg, Raven, and Duela Dent summon former Titans Nightwing, Donna Troy, Beast Boy, and the Flash (Bart Allen), who join them against Deathstroke's team.

[26] After Bruce Wayne returns, it is revealed that Cassandra's disillusionment was a ruse, and that she has willingly handed over her Batgirl mantle to Stephanie because she was acting under her mentor's orders in the event of his death or disappearance, and gone undercover, using Tim Drake as a regular contact.

[27] Following Bruce Wayne's public announcement about his intention to create a global team of Batmen, Tim visits Cassandra in Hong Kong, where she has been acting as an codename-less vigilante.

Just before departing, Tim gives Cassandra a copy of her old costume and tells her that if she chooses to stay and fight crime in Hong Kong, he hopes she will do it while wearing a Bat-symbol.

[10] Cassandra takes Tim up on his offer, and joined up with Bruce's new group, now wearing a heavily modified costume that uses her original outfit as a base.

[11] After a new supervillain named the Architect destroys three Gotham bridges with the help of explosives smuggled from Hong Kong, resulting in the deaths of dozens of civilians.

[28] During a stakeout at Oswald Cobblepot's nightclub, Cassandra is mocked and berated by Damian, who tells her that he is a better hero and that Bruce likely sent her to Hong Kong as a demotion.

[29] And after Dick discovers that the Architect plans to flood Gotham and kill thousands of civilians, Cassandra and Damian work together to dispose of the explosives that were supposed to sink the city.

[30] Cassandra later infiltrates a tournament for hired killers and rescues Red Robin, who had been captured and was about to be sexually assaulted by the half-sister of Ra's al Ghul.

Just as Cassandra and Tim fall into unconsciousness, the Cricket vows to face them again someday, and tells them that he hopes they will put up a better fight next time.

Her father, David Cain, is portrayed as a character named the "Orphan", who raises Cassandra alone and forces her not to speak but to "listen" to body movements and react accordingly with deadly precision.

In August 2024, DC Comics announced a new solo series for Cassandra Cain, marking her return as Batgirl in her own title after nearly two decades.

[35][36] Cassandra Cain also tries to defeat Failsafe (a robot designed by Batman to take him down in case he went rogue) but fails and is temporarily captured before freed.

She is an amazing hand-to-hand combatant and is highly skilled in several martial arts, including Kung Fu, Jeet Kune Do,[39] Muay Thai,[39] and Ninjutsu.

In Batgirl #67 (October 2005), Oracle performed a number of tests on Cassandra, determining the severity of the problem: "The language centers of your brain are all over both hemispheres.

It is explained that during the year in which Batman, Nightwing, and Robin were abroad, Cassandra and Alfred took it upon themselves to help develop the skills that she lacked due to her less than conventional childhood.

Like the other members of the Bat-Clan, Cassandra's Batgirl also wears a yellow-pouched utility belt which contains grappling hooks, batarangs, mini-explosives, tracking devices, a hand-held computer, binoculars, PlastiCuffs, and smoke pellets.