Orca (DC Comics)

Orca is the name of two fictional characters in DC Comics.
Publication history.
The Grace Balin version of Orca first appeared in "Batman" #579 (July 2000) and was created by Larry Hama and Scott McDaniel.
The Dean Toye version of Orca first appeared in "Aquaman" Vol. 8 #12.
Fictional character biography.
Grace Balin.
Grace Balin attends Gotham Gate College and quickly becomes fascinated with the ocean. She receives a Ph.D in marine biology and Bio-Medicine and takes a job at the Gotham Aquarium. She is a very charitable person who funds an after-school program involving the ocean for underprivileged youths. She also volunteers at a soup shelter and takes care of many homeless people. Dr. Balin is later involved in an accident that leaves her paralyzed, dependent on a wheelchair for mobility. She continues to work at the Gotham Aquarium until it is supposed to be closed for lack of funding. Grace experiments with spinal cord tissue regeneration using orca spinal cord tissue. The gene therapy studies and human experimentation that she was conducting are deemed controversial, resulting in her loss of funding. It is implied that Grace used a chemical formula that she derived from an orca in the aquarium on herself and that this is what caused her to transform into Orca. She is able to easily switch between being Orca and her regular appearance as Dr. Balin, although she is apparently still paralyzed as Balin even if Orca is fully mobile. Orca begins a crime spree in Gotham City by stealing a valuable diamond called the Flame of Persia from rogue millionaire Camille Baden-Smythe. After the theft, Batman becomes involved. Orca's dedication to what she perceives as justice conflicts with Batman's attempts to see that everyone is entitled to legal protection even if he dislikes them personally. Orca aims to sell the diamond and use the proceeds to help fund several projects for underprivileged people. After her attempt to sell the diamond back to Camille Baden-Smythe fails with the discovery that she had stolen the diamond originally, Orca attempts to kill her. Camille's security force shoots Orca several times, mortally wounding her. After an extensive underwater chase — Batman using an aquatic-equipped suit — she begins changing back into Dr. Balin in an underwater cavern, telling Batman that the only way that she can survive is if he gives her the rest of the chemical formula that turned her into Orca, and that this would permanently transform her into Orca. Although Camille tried to forbid Batman from giving her the formula, arguing that such an action would make Batman responsible for everyone she would subsequently kill, Batman states that they are all responsible for their own actions, as well as that he refuses to allow anyone to die. Having ingested the formula, Orca swims away, resolved to continue her current career. It is revealed that the jewel was then sold to its original owner and that the money was used to build a new recreation center near the aquarium as well as to "...gentrify a derelict waterfront tenement".
Orca is not seen again until she appears as a prisoner in the Slab during the Joker’s "Last Laugh" riots. She is able to escape during the riots with King Shark.
"One Year Later", Orca is found dead in the sewers under Gotham City. She appears to have been shot in the head by Harvey Dent's gun, although Batman is convinced Dent is not the true killer. He finds that her body has been partially eaten by Killer Croc. Orca's husband Terry was murdered by the Tally Man while he was being questioned about the disappearance of his wife by a private investigator Jason Bard. During the investigation it is revealed that Orca was working for the Penguin along with now deceased supervillains the KGBeast, the Magpie, and the Ventriloquist. Someone had contracted Orca and other supervillains to turn on the Penguin and rob one of his storage facilities. Harvey Dent catches them and instructs them to stay loyal to Penguin and to get any information they could about him. Dent is the prime suspect in their murders, but it turns out that they were orchestrated by the Great White Shark, who plans on becoming the top crime boss in Gotham. He manages to accomplish two tasks at once, weakening the Penguin's forces and transforming Harvey Dent back into Two-Face.
In the "DC Rebirth" relaunch, Orca and her Death Cycle are mentioned by Cheshire and Copperhead as some of the many villains who have attempted to kill Batman for Two-Face. Her first appearance is in "Nightwing" #11, where she is a part of a criminal group in Bludhaven called the Whale's Enders and is ordered to kill Nightwing. Grace was formerly a member of the Run-Offs, a rehab group for former Gotham supervillains, but left because she considered herself too much of a monster to relate to them (implying that her transformation is permanent). After Nightwing and the Run-Offs defeat her, she reveals that they were just a distraction for Carter Forsyth to be killed by the False Face Society.
During Raptor's invasion of Bludhaven, Roland Desmond demonstrates his power to the Whale's Enders by easily taking down Orca with his bare hands. The Whale's Enders try to replicate Grace's formula to transform themselves into whale hybrids to level the playing field, but fail miserably and dissolve after they are defeated by Nightwing. When Raptor starts wreaking havoc in the city by using Roland's Blockbuster formula on the citizens, the Run-Offs seek Grace's knowledge in developing an antidote to cure the affected people. Orca's biochemistry knowledge helps save the city and she rejoins the Run-Offs at the end of the story arc.
She makes an appearance in The Joker (2021) in a short story showing that she is now incarcerated in the women's section of Blackgate penitentiary following a parole violation set up by a member of the Royal Flush Gang at Blackgate who hires Orca to takeout the joker's lackey Punchline 
Dean Toye.
In the "DC Rebirth" relaunch, there is also another human/killer whale hybrid also called Orca. Sergeant Dean Toye is a member of the Aquamarines, a task-forced of military operates trained and transformed to combat Atlantis in case of a crisis. As the second-in-command to Major Rhonda Ricoh who has the codename of "Great White," Orca and the Aquamarines are dispatched by the government to kill Aquaman at the time when he was framed by the organization N.E.M.O. Orca and the Aquamarines are defeated by Aquaman and are detained by the Atlanteans as prisoners of war.
Powers and abilities.
The Grace Balin version of Orca has enhanced strength and endurance, although her strength has not been enhanced to the point where a trained fighter like Batman would have significant trouble with her on land. Her main advantage lies in her exceptional swimming abilities, allowing her to be at complete ease in water, able to swim under water for long periods without taking a breath, forcing Batman to use an aquatic costume to effectively confront her on equal terms.
The Dean Toye version of Orca also has similar abilities.
Other versions.
In the prequel comic to "Injustice 2", the Grace Balin version of Orca is shown to be a member of this universe's Suicide Squad. When the Suicide Squad is absorbed by Ra's al Ghul in his global conquest, she and Killer Croc are used as his heavy enforcers. It is later revealed that she is dating Killer Croc and is pregnant with his child. They are eventually married by Solovar and Ra's al Ghul deactivates their bombs for them to live a happy life. However, they decide to kill Ra's al Ghul and Croc severs Ra's al Ghul's arm before Gorilla Grodd arrives to take over. They let Grodd take over as revenge for Ra's al Ghul and to ensure the safety of their fellow squad members.
In other media.
The Grace Balin version of Orca appears in "The Lego Batman Movie", voiced by Laura Kightlinger. She assists Joker in his takeover of Gotham City. In preparing to help Batman fight Joker and the Phantom Zone inmates, Batgirl asks Orca what her powers are and she states "I'm a whale".
The Grace Balin version of Orca appears in "Lego Dimensions". She appears in "The Lego Batman Movie" story pack.