The 22-year-old - who plays Harry's arch-enemy Draco Malfoy - has filmed the last scenes of the final movie, Harry Potter And The Deathly Hallows, and wanted his fellow actors to have a lasting memento of their time on set.

"I wasn't supposed to say anything, but we've all got lightning bolts on our a***s," he quipped in an interview with The Sun. "No, I'm joking. But I did try and talk them into it. I thought it was a nice idea - maybe not on the a**e, but a little something. We talked about it but all wimped out."

Tom revealed that he and co-stars Emma Watson, Daniel Radcliffe and Rupert Grint had discussed their futures as filming drew to a close.

"We did the whole thing of where we thought each other would be in five years," he said.

He joked: "There were some shocking answers. There were some in rehab, drama teachers, Harry Potter convention runners.

"I'm a keen musician, so apparently I'm going to be doing Harry Potter The Musical."