A mechanical dragon that appears to fly without cables has been spotted over Orlando's Disney World Resort ahead of the opening of the park's New Fantasyland area.

Footage of the fire-breathing creature, gliding above audiences at a media and travel industry preview on Wednesday night, has been uploaded to YouTube by Disney's social media editor Gary Buchanan.

It is one of the highlights of New Fantasyland, part of the Magic Kingdom theme park at Disney World, Florida, US, which has doubled in size making it the largest expansion in the park's history.

New Fantasyland's expansion sees two new castles added to the theme park, including Prince Eric's castle above the Little Mermaid Under the Sea attraction, and the Beast's Castle, which will house the Be Our Guest restaurant, a ballroom and a gallery.

At nearby Belle's village guests can find Gaston's Tavern and hear a retelling of Beauty and the Beast by characters Belle and Lumiere.

Meg Crofton, president of Walt Disney Parks and Resorts Operations, said Fantasyland is a place for children to come in contact with princesses and heroes and from next year guests will be able to meet Disney princesses like Aurora and Cinderella in a dedicated Princess Fairytale Hall.

A Seven Dwarfs Mine Train roller coaster will open in 2014.

The new attraction is seen as Disney's response to the US$265m Wizarding World of Harry Potter, which opened at Disney's rival Universal Studios Orlando park in 2010. Based on the characters created by JK Rowling, the Harry Potter-themed attraction has been an amazing success, with attendance at Universal's Islands of Adventure theme park soaring 29 per cent in 2011.