Dr. Cassandra Knox was a female scientist who worked for Cobra
A Real American Hero comics continuity
Marvel comics continuity
Dr. Knox created a new, deadlier type of B.A.T. and charged it with hunting Scarlett. Encodings of Scarlett's brainwaves allowed the B.A.T. to track her.
Dr. Knox released the B.A.T. from a Cobra transport chopper in Salt Lake City, with orders to terminate Scarlett with extreme prejudice. Knox herself monitored the B.A.T.'s activities. During the battle, the B.A.T. fell into a cement mixer, which caused Dr. Knox to lose its monitoring signal. The transport chopper began to fly lower, trying to recover the signal. Scarlett attacked the copter with a rivet gun, so the copter began to shoot her. Scarlett escaped the chopper only to find the B.A.T. still functioning.
Scarlett used a garbage truck to crush the B.A.T. Even though the furious Knox wanted to kill Scarlett with her bare hands, the arrival of a squad of G.I. Joe Razor-Blade helicopters dissuaded her from doing it, so she escaped.
Devil's Due continuity
When Cobra Commander was captured, and Destro took charge of Cobra, Dr. Knox was hired to gain access to Dr. Mindbender's ultimate weapon - the Tempest. Knox was unable to gain control of the weapon, as she discovered it needed the palm-print of Mindbender himself.
When Cobra Commander returned and reclaimed his organisation, Knox was initially taken prisoner, but the Commander, tired of Dr. Mindbender's disloyalty, decided to make Knox Cobra's new chief scientist. Knox found a way to circumvent the problem of needing Mindbender's palm print to activate the tempest - by making a copy of his print as soon as he scanned it the first time. Cobra Commander executed Mindbender, and welcomed Knox into Cobra's high command. Knox promised the Commander she would not let him down.
Knox then assisted the Commander in unleashing the bio-weapon 'Death Angel' via the Tempest, but when G.I Joe forces stormed Cobra's monolith base, Knox was knocked out by Lady Jaye.
Knox later returned to the Commander's side when he took control of M.A.R.S from Destro, and helped to interface Cobra's systems with the M.A.R.S defence satellites.
Devil's Due G.I. Joe vs. the Transformers comics continuity
Doctor Knox designed a program that would enable Cobra Commander to control the bio-mechanical construct known as Serpent O.R. from afar. The program was placed into a viral delivery module, which Zartan attached to the (newly rechristened) Serpentor's neck during a melee with the android.
Sometime later, Dr. Knox spent several days with Cobra Commander in the tech room of a Terrordrome in Siberia, working over the blueprints of Serpentor and the viral delivery module. Knox noticed that Zartan and Baroness were spying on them from outside the sealed door, but Cobra Commander didn't care, for he would soon have the power of a god!
During a battle between Optimus Prime and Serpentor on Cybertron, the viral module came loose from Serpentor's neck, somehow allowing its code to initiate. By the time Cobra Commander gained control of Serpentor via neural uplink, the android had unleashed the power of the Matrix of Leadership and become Serpentor Prime — giving the Commander access to the accumulated power and knowledge of the Transformers race! Unfortunately, the Matrix feedback that Cobra Commander received during his subsequent defeat seemed to fry his mind.
This left Dr. Knox in a bit of a lurch.