Stan

Alistanathcalebiviteth, or simply Stan, was a Gallifreyan Time Lord of the Arcalian College, and a member of the Celestial Intervention Agency.

First incarnation
Stan's first incarnation appeared as a tall, middle-aged man with curly black hair. He wore an Edwardian ruffled shirt and matching trousers, but also a pair of blue tennis shoes and an orange "Stop the War" sign. He also carried a modern-looking briefcase.

He was considered a very promising recruit by the Celestial Intervention Agency, especially for his age: he was less than 400 years old, and still in his first incarnation, when he visited 20th century Earth and met Tabby Fellowes. He travelled in a TARDIS whose exterior was stuck in the appearance of an old phone booth.

Visiting a museum at night (unaware that this constituted trespassing since the place was closed for the night), he met Tabby Fellowes, a benevolent cat burglar who was attempting to steal a mysterious mask which Stan was startled to recognise as a dangerous alien artefact which the Time Lords thought they had destroyed long ago. 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. (PROSE: Tabby Cats And Time Lords)

Second incarnation
The newly-regenerated Stan appeared as a younger man with a round face, blond, wavy hair, and a matching goatee. Jumping right into action, he said goodbye to Tabby and made 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. By then, he had discarded his previous incarnation's outfit in favour of "an immaculate white jumpsuit" with a "dashing" red sash tied around his waist and a red carnation pinned to his lapel. The two then headed to Stan's first proper assignment, in the Greater Magellanic Cloud. (PROSE: Tabby Cats And Time Lords)