Doctor Who's Steven Moffat has hinted that the next series will focus on new monsters.
The showrunner told French websites Le Village and Reviewer.fr that he prefers devising original threats for the Doctor (Matt Smith) to face.
"I always say new monsters are better in Doctor Who because you fall in love with monsters when they're new," he explained.
"One of the temptations, particularly if it's a success is to keep repeating your hits, which means you hear it again and again and again."
The sci-fi drama's seventh run began shooting last month in Wales, with Saul Metzstein directing.
Sherlock star Rupert Graves, The Fast Show's Mark Williams and Harry Potter's David Bradley are among the guest actors confirmed to appear in the new episodes.
New executive producer Caroline Skinner recently promised that the latest series will "blow everybody's mind".
"We've got a lot of [the scripts] and the ones that are written are really, really epic and very exciting," she said.
Doctor Who will return to BBC One in the autumn.
