The actor was quizzed by USA Weekend about any big names who will be seen in the third run of the BBC One fantasy drama.
"I'll probably get whipped for it later, but I'll be fine. Fans of the Harry Potter films will see a few familiar faces. One of the great people who we just had recently was Miriam Margolyes, who features as Professor Sprout in the Harry Potter films, and she is just an absolute blast. That's an episode in the third series, the sixth, to look forward to," he said.
"And one I'm really excited about, and he hasn't been in yet, is Warwick Davis. I'm a huge fan of Willow from growing up, and he's featured in Harry Potter."
The 24-year-old also confirmed that Santiago Cabrera is to reprise his role in the upcoming series.
"I do know that Lancelot is coming back as well. We've been so lucky we've had people who want to be a part of the show, and we're always excited about that."
Davis will be the focus of Ricky Gervais and Steven Merchant's new comedy Life's Too Short.