- You may be looking for the real world Paul McGann or his invalid counterpart.
Paul McGann was an actor who portrayed the Doctor, (PROSE: Hospitality) or "Doctor Who", (WC: Peter Capaldi and Simon the Shy Cyberman Invite You to Breakfast with 7 Doctors) in the Doctor Who TV movie.
An older man and a boy expressed a sexual interest in the actor after the airing of the movie. (PROSE: Hospitality)
He was considered by the Twelfth Doctor to be one of the greatest actors on Earth. He was brought together, along with many other actors to portray "Doctor Who", for a special breakfast in "London's glittering West End". The Twelfth Doctor considered making an appearance, to "see what these fictions [were] like." (WC: Peter Capaldi and Simon the Shy Cyberman Invite You to Breakfast with 7 Doctors)
Behind the scenes
Evidently, "Paul McGann" here was, in both cases, intended to be an in-universe version of the real Paul McGann, who portrayed the Eighth Doctor. Although he was not given a clear in-universe illustration during the narrative of WC: Peter Capaldi and Simon the Shy Cyberman Invite You to Breakfast with 7 Doctors, or indeed PROSE: Hospitality, the end of the webcast included a screen featuring photographs of each Doctor who would be present at the event, in-costume as "the Doctor". If taken as an in-universe representation of McGann, this qualifies as the only in-universe illustration of the character outside of parodies.
In Doctor What 1, a Doctor called "...and I" appeared, a reference to Paul McGann's role in Withnail and I. Additionally, Paul's Withnail and I co-star Richard E Grant also exists in-universe.
In Portia Da Costa's erotic novel The Stranger, which featured an amnesiac character to parse as the Eighth Doctor, the mysterious stranger's true name was "Paul Bowman", obviously derived from Paul McGann.
The novel is of note to this Wiki due to both Father Time and The Gallifrey Chronicles referencing it a couple of times, however as the novel featured no legal link to Doctor Who, it is not currently covered by this Wiki.
A version of McGann appeared in the speculative story Father Time: "Set Visit", published in 2001.
Information from invalid sources
When looking back on the events immediately following on from the Seventh Doctor's regeneration into the Eighth Doctor in 1999 San Francisco, a later incarnation of the Doctor noted that he "looked like Paul McGann" in the footage he presented. (NOTVALID: Introduction to the Night)