The Doctor's grandfather

From Tardis Wiki, the free Doctor Who reference

According to one account, the Doctor had a grandfather. In an alternate universe, Patience tutored him, like she did the Doctor's father and the Doctor himself. (PROSE: Cold Fusion)

In the post-War universe, the Eighth Doctor painted a portrait of his grandfather in the basement of the Henrietta Street House. Scarlette described the figure as "an old man serious in appearance with a great red beard". While the Doctor said it was meant to be his grandfather, he made it clear to Fitz Kreiner that it wasn't a true representation but just an imaginary figure meant to represent his family for his upcoming wedding to Scarlette. Later, it was the only decoration he requested to be placed in the Zero Room, facing the bed. (PROSE: The Adventuress of Henrietta Street)