extract Cut down to relevant interesting parts.

David Tennant appears in one Harry Potter film and though his part isn’t big, his character is crucial to the story. Tennant is a prolific stage, television, and film actor who has appeared in numerous franchises as well as smaller roles across the course of his career. In the same year as Harry Potter, Tennant played the 10th Doctor in Doctor Who. These two massive franchises paved the way for Tennant’s career path. Since then, he has appeared in notable series like How to Train Your Dragon as Spitelout, the Star Wars franchise as Huyang, Broadchurch as Detective Alec Hardy, and Jessica Jones as Kilgrave, among many other roles.

The end of Harry Potter and the Goblet of Fire reveals that Mad-Eye Moody (Brendan Gleeson) has actually been Barty Crouch Jr. the entire film; having disguised himself with Polyjuice Potion. Barty Crouch Jr. is revealed to be the secret puppetmaster behind many of the calamities and victories that happened to Harry. It’s not obvious that Mad-Eye was an imposter but David Tennant improvised by licking his lips throughout the film, a trait Gleeson decided to mimic, signaling one of the small ways keen-eyed viewers could figure out the twist.

In an AMA on Reddit in 2020, Tennant promoted his podcast “David Tennant Does a Podcast With…” and answered fan questions. In response to one question about his time on Harry Potter, Tennant replied,

“I wasn’t on Harry Potter for all that long. I think I did 10 days or so over a year, so I always felt a bit like a visitor. But it was great to be part of something so extraordinary. They only gave me a little chair though, so when everyone was sat around Maggie Smith and Michael Gambon and Alan Rickman and Daniel Radcliffe all towered over me in these fancy cast chairs. Still a pleasure to be there though.”

It’s not a surprise that David Tennant did not feel completely at home on the Harry Potter set. He only had a small role and was coming into a film with actors who had known each other and worked together for years. The rest of the AMA focused on Doctor Who and Broadchurch. So like many of his fans, the time David Tennant spent on Harry Potter was memorable, though it wasn’t as significant as the rest of his career.