Robert Englund left his female castmates reeling in horror when he first appeared in full costume as Freddy Krueger in 'A Nightmare on Elm Street'

Heather told People to mark the 40th anniversary of the release of late director Wes Craven's slasher classic: "We were shooting a scene - it's everyone's favourite - where Nancy goes into her school and she walks down the hall and then she walks down some stairs and there's Freddy down in the dungeon of the school.

"The moment when he pulls aside this curtain and he's revealed in the smoke.

"He had such great body language that he developed for Freddy. It was all right there in full force.

"And then that hat was tipped over his eye and he had one shoulder higher than the other - it was a full Freddy look that I had never seen before," she continues.

"And I realised that it was totally frightening. It did set me back a bit."

Heather added the petrifying creation Robert and Wes had put together also hit hard in a scene where he appears in an alley, scraping his razor claws on a wall and cackling.

She said: "There were also the scenes in the alleyway, where Freddy says his famous 'This is God' line, and I remember being there, realising how frightening that particular line would be for so many people."

In that scene, actress Amanda Wyss, who played Tina Gray in the flick, who terrorised by Freddy.

Heather added about the physical toll of her role: "There was a lot of running. All of those scenes where there's so much action, so much fighting, I really relied upon a lot of my training as a dancer.

"Of course, we had wonderful stunt people to help us."