Cyberman (The Girl Who Loved Doctor Who)

From Tardis Wiki, the free Doctor Who reference

A Cyberman travelled through the Void following the Battle of Canary Wharf and appeared in a parallel universe where the Doctor's adventures existed only as a fictional series titled Doctor Who.

Equipped with an experimental dimensional compass, it determined this Earth would be ideal to cyber-convert, as the Doctor was fictional and therefore posed no threat. The Cyberman "blew a hole" from the Void into this universe which also sucked in the TARDIS from the Doctor's universe. The Doctor stated it would have been capable of converting the entire planet in about two weeks.

After the Eleventh Doctor arrived in the parallel universe, the Cyberman followed him to the house of a young girl named Ally. The two lured it to the set of Doctor Who, which incidentally was filming an episode about the Doctor visiting the "real world", as the series followed the actual Doctor's adventures. The Doctor and Matt Smith, the actor who played him, confused the Cyberman long enough for the TARDIS to gather its interdimensional location from the Cyberman's dimensional compass, and the TARDIS sent the Cyberman back into the Void. The Doctor was able to use this information to return to his home universe. (COMIC: The Girl Who Loved Doctor Who)