Alexandra was the leader of the Odessa Mob after her father's death.
When the great gang war broke out in Gotham, Alexandra lead the Odessa Mob against the Escabedo Cartel, believing that they were the ones who drew first blood. Batman tried to stop her, but she escaped and Batgirl was sent to follow her. However, Alexandra managed to lose Batgirl and reached safety. Later, Alexandra was summoned by Penguin along with several other crime lords, in order to bargain mercenaries in exchange for money. Alexandra refused, but later she realized that her gang neede to join another to survive the gang war. Alexandra met with low profile crime lord called Sanuders and proposed him to join against Scarface. However, when Saunders and his gang arrived at the meeting place, they realized that they were double crossed by Alexandra, who was already allied with Scarface and together, they eliminated Saunder and his gang. After that, Alexandra planned the assassination of crime boss, Henry Aquista's daughter Darla Aquista.
As the gang war escalated and after the death of the young girl, Alexandra was approached by Black Mask, who after killing her bodyguards, offered her protection from the onslaught from all her enemies in Gotham.
Kosov wasn't seen during the rest of the gang war and she appeared, leading her gang once again after the final stand between Batman and Black Mask. She pledged loyalty to Black Mask in the name of the Odessa Mob and acknowledged him as the undisputed crimelord of Gotham.
Alexandra joined The Mad Hatter and a mind controlled Killer Croc under Black Mask's command and together they kidnapped a kid that they used to drive Batman's attention away from them during the final confrontation. After this, Alexandra led the Odessa Mob against the Hill Gang and they were defeated in the battle. Onyx, the leader of the Hill, defeated Alexandra and warned her not to meddle with her gang again.
A few days later, Batman captured Alexandra and questioned her about Black Masks's activities and plans. Alexandra refused to talk but after a brief threat, she told Batman everything she knew. Batman left her tied-up and removed the blue gem from her eye socket.
Some time later, Alex was captured by the police and she was indicted for the conspiracy to commit murder during the events that ended up with the death of Darla Aquista.
- Driving: Driving a stardard vehicle, Alexandra was able to lose Batgirl while she was chasing them with the Batcycle.
- Marksmanship: Alexandra is able to shoot perfectly aimed shoots at small objects like ropes with extraordinary precision.
- 9 Appearances of Alexandra Kosov (New Earth)
- 3 Images featuring Alexandra Kosov (New Earth)
- Quotations by or about Alexandra Kosov (New Earth)
- Character Gallery: Alexandra Kosov (New Earth)