Tabby Fellowes
Tabby C. Fellowes, also known as T. C. and, briefly and mistakenly, as Gulindavagoodavish, was a cat burglar and the daughter of her predecessor in the role, "Black Cat" Fellowes. She had long red hair and green eyes.
Black Cat taught his daughter everything he knew about high-risk heists, as well as inculcating in her a strong reluctance to ever resort to lethal force to get her way. He foresaw that she would become even more skilled than he was. Eventually, Black Cat was arrested on trumped-up charges by Kevin Chaney in reprisal for attempting to steal his mysterious mask; Chaney, actually the Tremas Master, then arranged for him to be murdered in a prison brawl. Tabby took over his operation and decided to avenge his memory by completing the theft of the mask in his stead.
At the museum, she met a Time Lord, Stan. Although she did not believe his claims about being a time-and-space traveller or the mask being an alien artefact, she teamed up with him as they fled from security, and returned with him to the museum later, using Stan's ultrasonic electron diverter to deactivate the burglar alarms. They were confronted with the Master himself, but thanks to Tabby's quick thinking, he was forced to flee with the mask. He'd injured Stan, whom Tabby escorted back to his own TARDIS and saw regenerating into a new, younger man. Aghast, she said her goodbyes to Stan as he prepared to return to Gallifrey to give the mask to his superiors at the Celestial Intervention Agency. Watching him go, she regretted that she had not seized her chance to become a space traveller. To her surprise and joy, the TARDIS returned moments later from her perspective. Stan explained that it had been three weeks for him and he had been promoted to a permanent C.I.A. field agent, and got Tabby to agree to becoming his companion. The two then headed to Stan's first proper assignment, in the Greater Magellanic Cloud. (PROSE: Tabby Cats And Time Lords)