Shana O'Hara, aka Scarlett, a crossbow-toting southern belle with a history in martial arts, is a prominent member of the G.I. Joe team. She usually has a thing for the enigmatic ninja warrior Snake-Eyes.
Marvel Comics continuity
G.I. Joe Meet the Transformers
Scarlett and several other Joes were overseeing a test of Power Station Alpha, which was interrupted by the appearance of a giant transforming robot. After the Transformer was destroyed, it was followed by a much larger robot which called itself Superion. G.I. Joe's forces were overwhelmed by Superion, so Scarlett called for backup.
The Transformer they destroyed was eventually determined to be their friend! Scarlett stood nearby while Mainframe attempted to rebuild him. As the Autobot Ratchet arrived to help, it was announced that Cobra would be teaming up with G.I. Joe and the Autobots against the Decepticons to keep them from destroying the world with Power Station Alpha. The newly rebuilt Transformer, now named Goldbug, escorted Scarlett and the Baroness to Power Station Alpha with the intention of placing detonators inside. Without G.I. Joe's consent, Baroness set the timers prematurely, much to Scarlett's frustration.
G.I. Joe Starring Snake-eyes/Generation 2
While Scarlett was pretending to have defected to Cobra, Snake-Eyes was forced to stab her to convince the terrorist organization of her new allegiance. While none of her vitals were damaged, she was nevertheless hospitalized at the Cobra's castle fortress, where Cobra scientist Doctor Biggles-Jones confronted her about her true intentions.
Just as Dr. Biggles-Jones had revealed that she too was a double agent, the newly rebuilt-by-Cobra Megatron snatched her away, wishing to experiment on the scientist's brain. Scarlett, despite her wounds, fought her way out of the Cobra compound and confronted Megatron. Her audacious ultimatum was cut short when a small group of Autobots sent by Optimus Prime (Hot Spot, Brawn, Chase, Override and Steeljaw) arrived to attack Megatron. While the large-scale battle raged, Scarlett used the opportunity to attack Cobra Commander. A save by Snake-Eyes reunited the pair.
With all of the Autobots destroyed (minus Skydive), Megatron stole the Ark with Dr. Biggles-Jones still in tow. It was Skydive and Spike Witwicky who managed to sneak aboard and bring the doctor home, though at the expense of Witwicky's life. Returned to safety, Dr. Biggles-Jones greeted Scarlett with a much-needed hug.
Devil's Due G.I. Joe vs Transformers comics continuity
When Cobra unearthed and reprogrammed the dormant Transformers aboard the Ark and used them to take over the United States government, Scarlett was among the members of G.I. Joe, the anti-terrorist force created to stop them. The initial attack cost Snake-Eyes not only his voice and face, but also his family, which was nearby. Scarlett learned of Snake-Eyes loss from Doc and wondered how he could go on after suffering through so much in one day. Her first duty as part of G.I. Joe was to guard the SPS Center from an attack by Cobra's commandeered Transformers. The attack came, overwhelming and surrounding Scarlett's group until they were rescued by the free agents Bumblebee and Wheeljack. A final raid on Cobra Island by the combined G.I. Joe and Autobot forces prevented not only Cobra from taking over the world, but also a government-launched warhead from nuking the island, which would have subsequently ignited the island's energon, cracking the planet in two.
Two years later, Scarlett was part of a G.I. Joe assault team sent to a warehouse in Boston to stop an international arms ring affiliated with the Dreadnoks from selling Cybertronian technology on the black market. The Dreadnoks, now augmented with cybernetic attack limbs, were apprehended.
Dreamwave Transformers vs G.I. Joe comics continuity