Eddie Redmayne was worried about "screwing up" 'Fantastic Beasts and Where To Find Them'.

Eddie Redmayne

Eddie Redmayne

The Oscar-winning actor is a huge fan of the 'Harry Potter' movies and admitted to some nerves about taking on the role of Newt Scamander in the upcoming spin-off.

He told The Observer Magazine: "Of course you feel pressure. Also, particularly because I loved the Potter films. There was something so warming about being able to dive back into that world every year or two. And if you've enjoyed something, you don't want to be the one who comes in and screws it up.

"But pressure's there with every film. With 'The Theory of Everything' it was knowing Stephen and Jane Hawking and the family would see the film. With 'The Danish Girl' it was all the people that I'd met in preparation for the film who came from the trans community. It's pressure here of a different type, which is called hard core fandom."

And Eddie admitted the die-hard fans can make him nervous.

Speaking about taking to the stage at Comic-Con in San Diego this summer dressed as Newt, he said: "That was so intense. The whole situation is created like you are meant to go on like a rock star. I remember feeling really nervous beforehand, waiting in the wings, and [co-star] Colin Farrell was giving me a little back massage going, 'It's going to be fine, Eddie, it's going to be fine.'"

He also recalls the six-month shoot as arduous, explaining: "For this, it was working with a lot of invisible creatures that weren't there and trying to find a way to negotiate that. And 'Theory' and 'The Danish Girl' were both eight-week shoots and this was a six-month shoot, so it's the difference between a sprint and a marathon. So, there were moments on this where I was like, 'No, no, no, this is the hardest.' I think it's probably just human nature."