After featuring in a regeneration scene in 'The End Of Time Part II' on New Year's Day, Smith starts his career in the lead role in Doctor Who this Easter.
Smith told The Guardian of his Doctor: "He's a little reckless. He'll walk into a room and have a million things to do.
"And, as opposed to knowing exactly how to get out, he'll take it up to the precipice: don't know, don't know, don't know, and boom, there's the idea.
"And it's a bit mad and reckless. It's very doof, doof, doof. And he's got a companion who I think is the hardest to handle. And she's quite mad. But The Doctor's quite mad as well. So together..."
When asked if his incarnation of the Time Lord will be melancholy, he replied: "I think it's impossible to escape that with The Doctor.
"He's lost so many people and devastated so much... bad or good, he's brought whole empires down. He's seen a lot, and that's part of his personality. But that's also what gives him such joy and effervescence."digitalspy.co.uk