Very little is known of the Baroness' past, except that she was on hand for the Tet Offensive in Southeast Asia, 1968. Visiting her brother, Anastasia is present at a meeting with indigenous relief workers that Eugene was financing. Arriving at a warehouse expected to be full of medical supplies he had donated to their cause, Eugene found nothing but questions and suspicions. When two soldiers arrive, the Baron ushers his little sister into a private office while he has words with them. Discovering they have sold his supplies for money with which to stage their offensive, Eugene is murdered. When Anastasia opens the door, she finds an American soldier standing over her brother with a smoking .45 caliber pistol.
Struck with overwhelming grief, and immediately blaming the American soldier for her loss, the Baroness is inconsolable. She is escorted from the scene as Destro (James McCullen the XXIII) and his son (James XXIV, the current Destro) enter. Destro discovers that Eugene wore a bulletproof vest, easily capable of stopping shots from Snake-Eyes' .45 caliber handgun. He deduces the truth and clears Snake-Eyes of the crime; too late for the Baroness to hear, and far too late for her to care.
Frustrated and angered, the Baroness spends years decrying the hypocrisy of the American Government, becoming an active participant in militant revolutionary groups, eventually becoming a member of Cobra. In the time between these two events, she crosses paths with James McCullen XXIV, and the two share a romantic relationship (the extent of which has never been revealed).
The Baroness is instrumental in Cobra's first major offensive against G.I. Joe: Operation: Lady Doomsday. Posing as a reporter, Baroness abducts Dr. Adele Burkehart and brings her back to Cobra’s island fortress. When the G.I. Joe team stage a rescue attempt, the Baroness disguises herself as the Doctor to lure the Joes toward the airfield, while the Commander make good his endgame scenario. But the Joes prove more than competent, and the Baroness is taken prisoner, only to find herself back at the Spanish Fort when G.I. Joe makes its final assault. Although the Commander is wounded, the Baroness eludes the Joes, and the two make their exit through a secret tunnel. The Baroness then pilots a small aircraft, saving the Commander from the fort's explosive destruction.
As Cobra's second-in-command, the Baroness is on hand for many of Cobra's schemes, including the Commander's attempt to steal the G.I. Joe MOBAT during a parade in New York City, and a tireless assault on NASA's spy satellite rescue mission. The Baroness is also present when Cobra takes Snake-Eyes prisoner, and Dr. Venom subjects him to the Brainwave Scanner. This meeting is significant for the fact that in the years since her brother's death, Snake-Eyes has been through so much trauma and disfigurement that he is completely unrecognizable to the Baroness. She remains unaware of her connection to Snake-Eyes for a long time after this initial meeting.
When the Cobra Commander first contracts Destro, to salvage a mission in Alaska, the Baroness is forced to reveal her past associations with the masked man. The Baroness is then ordered to Sierra Gordo to oversee the transfer of Dr. Venom's plague toxin, and set a red herring clue for G.I.Joe. Not interested in traipsing through the jungle herself, she trusts the Cobra courier, Scarface, to leave a false transmission embedded with a microdot in Cobra’s abandoned forest outpost.
Evading the G.I.Joe assault, the Baroness and Scarface escape in a plane, but the Baroness cannot pass up the opportunity to blow up the small island where Snake-Eyes, Kwinn the Eskimo, and Dr. Venom are locked in battle. Just before the bombs hit, Snake-Eyes pushes the other two into the island bunker, and all three vow revenge on her.
Confronting Destro about his connection to Scarface, the Baroness is forced to accept her beloved James' new identity as Destro, but also demands proof of his faith in her. In a gesture of love, Destro removes his mask, and the Baroness swoons, overcome by her feelings for Destro, and the situation it puts the both of them in.
The Baroness then accompanies the Cobra Commander as he visits Cobra's secret lab in Springfield, Vermont (not to be confused with Cobra’s true Springfield headquarters, located in a different, undisclosed state). Testing Dr. Venom's toxin, both are shocked to see the plague toxin, designed to be dormant in the host for weeks, kills instantly. Not only has Dr. Venom has betrayed them, but the G.I. Joe team has discovered the location of the lab. How?
Secretly, Scarface is working for Destro, and switched out the Commander’s microdot, which would have pointed G.I. Joe to a false headquarters. Instead, Destro's microdot gives G.I. Joe accurate intel on Cobra's lab in Vermont. Having unwittingly put his beloved Baroness in the crossfire, Destro mounts a rescue operation, meant to stall G.I. Joe while the Baroness and Cobra Commander make their escape.
Suspicious of Destro, the Commander enlists Major Bludd, a hired mercenary, to dispose of Destro during a night attack on Washington. As the driver of Major Bludd's HISS Tank, the Baroness sees his treachery, and swerved sharply to save Destro. The HISS goes out of control and rolls on its side, leaking fuel in the middle of a firefight. Badly hurt, the Baroness begs Major Bludd to help her get free, but he leaves her alone as the HISS explodes around her.
Seemingly killed in the fight, the Baroness is, in fact, rescued after the battle, and brought to Bethesda Naval Hospital where she lays severely burned, and in a coma. When the G.I. Joe Grand Slam takes Major Bludd into custody, the Baroness is moved to G.I. Joe headquarters in Staten Island as well. Luring Cobra into attacking the base after they capture Scarface in Tripoli, Libya the Joes instigate a major skirmish at their own headquarters. During the battle of PIT I, Major Bludd kills General Flagg, and frees himself. Taking the Baroness, he leaves Scarface for dead, and escapes in a Cobra FANG.
When she awakens from her coma, Major Bludd takes the Baroness to The Bern Institute in Switzerland. Under the alias "Baroness DeCobray", they hire Dr. Hundtkinder to perform reconstructive surgery on her face. Recovered from the surgery, the Baroness enters into a partnership with Major Bludd to blackmail Cobra Commander with the information they have about Destro's assassination. Meeting him in Lucca, Italy, they are double crossed when the Commander unleashes Storm Shadow on them, and G.I. Joe agents Duke and Roadblock crash the party. Fleeing the scene, the Baroness, Major Bludd, and Storm Shadow manage to evade capture, but Cobra Commander is not so lucky.
Returning to Springfield, the Baroness tells Destro the truth about the Commander's attempted assassination, as Destro reveals a bug he's placed in Storm Shadow's sword, which will allow them to track the ninja. The Baroness recruits Firefly and Wild Weasel to locate the signal, and dispose of Storm Shadow. However, the ninja has already discovered the bug, and mailed it to another Cobra operative: the enigmatic Zartan who lives in the Florida Everglades. With Firefly and Wild Weasel now prisoners, the Baroness and her allies are startled to find the Commander has returned, quickly rescued from G.I. Joe by Storm Shadow.
Placing Major Bludd in Springfield's underground dungeons, the Commander takes Baroness and Destro to meet Zartan in Florida. After a firefight with G.I. Joe, the Commander orders her back to Springfield, to prepare for his return. Immediately, however, she visits Major Bludd in prison, and frees him in exchange for his help in planning the assassination of Cobra Commander.
Recruiting Billy, a young boy who works with the Anti-Cobra Underground (the same boy who helped Snake-Eyes escape Springfield after his introduction to the Brainwave Scanner), the co-conspirators begin practicing for the heinous act. She even takes pity on Billy when Major Bludd snaps at him for screwing up at the rehersal of the assassination attempt, showing her tender side and perhaps, motherly instincts. Another example of the Baroness' tender side is when she tells Dr. Minderbinder that she likes some of Major Bludd's poetry. When at last the rally is at hand, the Baroness is confronted by Destro, who abhors the idea of using a child as an assassin. But by then, Major Bludd is committed, and the Baroness finds her loyalties wavering. During the rally, Destro identifies Billy, and frantically rushes the stage. Stopping both the assassination, and Storm Shadow's retaliation, Destro reveals Billy's identity, as none other than the Cobra Commander's own son.
Billy is put on trial by the Commander and Destro, who is overcome with empathy for both father and son, and the Baroness fears that she and Major Bludd may be revealed as his partners. But Billy is much stronger than he seems, and resists even the Brainwave Scanner, successfully keeping their hands clean of the whole affair.
After the assassination attempt, the Commander begins working closer with Tomax, Xamot, and Professor Appel on the creation of Cobra Island. The Baroness and Destro find themselves eager to get back in his good graces. Looking for a new weapon, they contact Dr. Mindbender, offering to help him test his experimental creeper vines, and more importantly, their android delivery system. Although the test is thwarted by Lady Jaye and a group of G.I. Joe recruits, Mindbender and the BATs are brought to Cobra Island to meet the Commander.
When they arrive, the Island has been infiltrated by Snake-Eyes and Storm Shadow, while a G.I. Joe rescue team waits in the waters off the coast. While Mindbender attempts to prove his mettle, the Baroness leads a Cobra force to the beach, where she is confronted by an exhausted and badly injured Storm Shadow. Not wanting to take a chance that Billy told him about the assassination plot during their time away from Cobra, Baroness shoots him down, seemingly killing the ninja.
Not long after, G.I. Joe is given the location of the real Springfield, and the Baroness assists Destro in evacuating the town. During the battle, Dr. Mindbender's greatest experiment is conducted, and Serpentor is created. Thought dead, Storm Shadow is also "resurrected" in Springfield and flees the GI Joe attack with the Dreadnoks. Destro manages to successfully evacuate the entire town as Serpentor fights a holding action. Although the Baroness suggests they leave, and garner all the glory themselves, Destro chooses to extract Serpentor and his forces, furthering the rift between the formerly romantic couple.
Upon reaching Cobra Island, Serpentor begins his usurping of the Commander's leadership, and the Baroness is quick to take up with him, seeing the reins of power being passed. When the Commander and Destro are buried alive under PIT II, the Baroness flies a Rattler over the rubble, and drops a wreath to mourn the passing of her estranged lover.
For a time, the Baroness allies herself wholly to Serpentor, and is in charge of the Terrordrome operation in Sierra Gordo when G.I. Joe agent Flint is captured and brought into the base. When Mindbender subjects him to the Brainwave Scanner, and gets no facial reactions, he suspects that the Joe is wearing a mask. Pulling it off, the Baroness confirms the identity of the massively scarred face beneath: it is actually Snake-Eyes in disguise. As G.I. Joe attacks the Terrordrome, Snake-Eyes is removed, along with the Scanner, to Cobra's new Consulate Building in New York.
As he is subjected to the Scanner again, the Consulate is attacked by Scarlett and Storm Shadow, eager to rescue their ally. Disguised as a late-night cleaning lady, Scarlett infiltrates the consulate while Snake Eyes' ninja brother breaks into the building by using the New York City sewer system. Using an X-ray scanner, the Baroness confronts Scarlet, but she is surprised when Snake-Eyes’ wolf, Timber, leaps out at her. While Storm Shadow rescues Snake-Eyes upstairs, Scarlett overpowers the Baroness, strips her of her uniform and leaves her bound and gagged in a nearby closet. Fighting their way to the lobby, Snake Eyes and Storm Shadow are then "captured" again by "the Baroness" and walked right out of the front door.
Later, the G.I. Joe team causes a massive disruption of the Consulate in a successful bid to place a wire tap on the building. Defeated, the Baroness is recalled to Cobra Island where a schism has occurred in the leadership of Cobra: Cobra Commander has returned. With the Baroness able to identify the Commander's real face, she is put in a transport chopper with him, and removes his helmet. Underneath is not the Commander, but one of the Crimson Guardsmen; namely, Fred VII. Claiming that the Commander retired to be with his son Billy (a lie, Fred actually shot and buried the Commander in Denver), the Baroness goes along with the false Commander, and usurps control of Cobra from an embarrassed and unpopular Serpentor.
Now in de facto command of Cobra, the Baroness is forced to take Fred VII on a mission into orbit to destroy a spy satellite threatening to undo Serpentor’s Terrodrome plot. When the Cobra Shuttle is attacked by the G.I. Joe Defiant, Baroness is knocked out cold, leaving Fred VII to lead Cobra to a slim victory. Now cocky, and drunk with power, Fred drags the Baroness' image down with him, and he ham-handedly leads Cobra to defeat in Frusenland, where Battleforce 2000 discovers the truth about the Terrordromes, despite Baroness' best efforts to defeat them.
Returning to Cobra Island, the Baroness is in attendance as Serpentor's lackey, the Star-Viper returns from a mission to infiltrate G.I. Joe's new base, PIT III, in Utah. Looking for a clear victory to win support back from the troops, the ceremony turns into a battle of words that erupts in the Cobra Civil War. As the leader of the first offensive, the Baroness is taken prisoner by Serpentor, and strapped to the front of his HISS tank to deter anyone from firing on him.
Into this all-encompassing war, the G.I. Joe team arrives to bolster Serpentor's ranks, while Destro makes an appearance with his own faction: the Iron Grenadiers. While G.I. Joe, Serpentor, and the "Commander" tear each other apart, Destro takes the airfield, and waits for his opportunity. Just as Fred’s army seems lost, Zartan fires an arrow and slays Serpentor from across the battlefield. With his leader fallen, Mindbender calls for a truce with the "Commander". United against Destro, the reunified Cobra is surprised to find that Destro wants only one thing: the Baroness.
Taking his prize, Destro retreats to his yacht. She reveals the true identity of the current Commander, and together they bear witness to G.I. Joe's unceremonious withdrawal from the Island. After helping the Joes clear their reputation in the wake of the Civil War, Destro and Baroness retire to Castle Destro in Scotland, eager to leave the intrigue and danger behind them. Sadly, the "Commander" wants his enemies routed, and stages an assault on Destro's castle. Turning the situation to his advantage, Destro captures the "Commander", and effectively takes control of Cobra.
Expecting favored status in this new unified Cobra, the Baroness is displeased to discover she has been paired with Zarana to run the Cobra Consulate in New York. The two even engage in a cat-fight which ends up with Zarana pushing the Baroness out of the side-door of a Cobra helicopter in mid-flight. The Baroness, however, manages to catch on to one of the helicopter's wheels just as it lands on top of the Cobra embassy.
Zarana has implanted false memories into G.I. Joe members Clutch and Rock 'n Roll in Broca Beach. Betraying Zarana, the Baroness leaks word that the Joes will be moved to a Cobra submarine off the New Jersey shore where they will "escape." At the same time, Snake-Eyes and Scarlett have journeyed to Switzerland to fix Snake-Eyes' face. In another moment of fate, Snake-Eyes meets with Dr. Hundtkinder, the same surgeon who treated the Baroness. Faxing her a photo of Snake-Eyes before his disfigurement, the Baroness realizes that he is the man who shot her brother. Unwilling to let him slip through her fingers again, now that she knows the truth, the Baroness sabotages Zarana's van, allowing the Joes to capture the Dreadnoks, and rescue Clutch and Rock 'n Roll. Locked up in GI Joe Headquarters' sickbay, Zarana is listed in fair condition as, perhap under the influence of painkillers,she tells the Joe's about the Baroness' trip to Switzerland. But it is too late.
The Baroness combat assaults the Bern Institute in an out-of-control spree of violence. Trapping Scarlett and a recovering Snake-Eyes, she shoots Scarlett in the head, and takes Snake-Eyes back to New York. Holding him in the Consulate's basement, Baroness is ready to watch the Paine Brothers torture Snake Eye to her pleasure, but Destro arrives to get answers concerning Zarana's capture. She informs the brothers to watch Snake Eyes, but she is forced to keep a straight face as Snake-Eyes overpowers the Paine Brothers and escapes into the Consulate proper. Meanwhile, Stalker, Storm Shadow and former Crimson Guardsman (Fred II) Wade Collins have been listening to the proceedings on the G.I. Joe wire tap. Taking the opportunity to rush the Consulate, they manage to get halfway up the building before Snake-Eyes detonates a huge amount of C-4, setting the top of the building on fire, and threatening to topple the entire penthouse. The Baroness and a small force of Cobra Troops have barricaded themselves inside, and watch helplessly as Storm Shadow scales the side of the building and prepares to enter the penthouse.
Once inside, Storm Shadow calls for Snake-Eyes, who reveals himself disguised as a Cobra troop. The two of them decimate the entire Cobra army, just as the building gives way under the massive damage, caused by the explosions. The Baroness falls, only to be caught by Snake-Eyes. Still filled with hate, she pulls her pistol on Snake Eyes when Destro returns in his helicopter and explains to her what he and his father saw that day back in Tet '68. Confused the Baroness is about to pull the trigger when another explosion rocks the building. Snake Eyes loses his grip and she plunges to her death only to be rescued this time by Storm Shadow, who tells her that he is not going to let her take the easy way out with all of her sins she has been carrying.
The ninjas help her onto Destro's chopper, and are rescued themselves by the G.I. Joe Tomahawk. Broken by the revelation of her misguided hatred, the Baroness plans to leave Cobra, and figure out where her life is headed which even leaves Hawk, the commander of the GI Joe team, wondering if it is really possible that someone like the Baroness can really change. In a moment of absolute devotion, Destro removes his family mask, and tosses it aside. Together, James and Anastasia retire from Cobra.
After leaving the Iron Grenadiers to Darklon, the couple returns to Castle Destro and enjoys a period of quiet reflection. However, in their absence, Cobra undergoes a dramatic revolution as the original Cobra Commander returns, and buries most of Cobra's High Command in a freighter under the volcano on Cobra Island. After a failed attempt to kill Storm Shadow, the Commander turns his sights on the last two traitors to his cause: James and Ana.
Tipped off to the scheme by Metalhead, Destro's spy in Cobra, the couple prepares to defend the Castle from a full assault. Destro and the Baroness manage to flee the Castle before it is destroyed, but while fleeing, the Baroness is hit and taken prisoner by the Cobra Commander. Subjected to the Brainwave Scanner, the Baroness is implanted with commands while the Commander wages an all-out Search and Destroy bounty on Destro. When the tables are turned, the Commander not only agrees to return the Baroness, but to give Destro the Silent Castle in Trans-Carpathia, in reparation for the Castle he destroyed.
In a double cross, the Baroness' hypnotic suggestions are activated by radio signal from a Cobra Hurricane. But before the Baroness can overpower Destro, they are attacked by Slice and Dice, who lead the Red Ninjas that dwell in the Castle's subcellars. As they fight for survival, the G.I. Joe team (called for protection by Destro) fights with an advance team of Cobra troops. The G.I. Joe Ninja Force arrives to defend Destro, while the Commander shows up to personally handle the matter, and the fighting escalates on all sides. But when they get a moment alone, Destro touches the Baroness' heart, and reminds her of his promise to always love her, as long as Castle Destro stands. Then, in a grand gesture of his love, he activates a series of levers in the Silent Castle, causing it to transform, and reconfigure into a larger, more majestic version of Castle Destro, proving his love is everlasting.
Making a second attempt to retire from the war, the Baroness grows bored of the mountain estate. But all too soon, the Cobra coils around them again. This time, the Commander succeeds in capturing them both, and locks them in a sewage drain under the Castle's subcellar. Breaking their bounds, Destro and the Baroness enter the myriad of secret passages in the walls of the Castle. Buying time before a G.I. Joe extraction team can rescue them, Destro once again reconfigures the Castle into a nightmare structure halfway between his Scottish estate and the Cobra Headquarters. Escaping with Snake-Eyes and Storm Shadow, Destro and the Baroness ally themselves with G.I. Joe and are taken to an abandoned Cobra Island, where they meet Zartan. After revealing Cobra's plans to revive Dr. Mindbender, Zartan returns to Trans-Carpathia with the couple, and takes back the Castle from a skeleton crew of Cobra troops.
Enjoying another short respite from Cobra, the trio is joined by Billy, returned from parts unknown. All too soon, however, the Cobra Commander arrives, and activates brain implants in both Destro and Zartan, bending them to his will. Although the Baroness and Billy utilize the Castle's secret passages to evade capture, they are thwarted by Destro himself. After being tortured for a time, Billy is ready to crack, and the Baroness does her best to keep him together. But Billy turns on his cellmate, ratting her out for trying to escape. When the two of them are brought up to the control room, Billy makes a mad dash to the console and launches an intercontinental ballistic missile, alerting G.I. Joe to the goings-on in Trans-Carpathia.
In return for deceiving him, the Commander not only kicks the Baroness in the face, but proceeds to capture Storm Shadow, and reconfigure all three of their minds with the Brainwave Scanner. As Snake-Eyes arrives to rescue them all, the Baroness emerges as part of Cobra Renewed, and helps route Snake-Eyes and the G.I. Joe extraction force. When the Commander is temporarily taken hostage, the Baroness steps up, and assumes control of Cobra, reestablishing her abilities as a field commander.
The series ends here, with the Baroness still a willing member of Cobra.