David Walliams, a life-long Doctor Who fan, debuts in the episode The God Complex this Saturday. Karen Gillan has said it’s one of her favorite performances this season.

Believe it or not David Walliams did a Doctor Who spoof back in 1999 along with Mark Gattis who most recently penned the Night Terrors episode.

How do you think Walliams’ mole character will stack up?