Heidi Klum towers over her Halloween costume party

Heidi Klum had to practice walking in her outrageous Halloween costume as she "couldn't really bend anything".

The 37-year-old model throws a star-studded party to celebrate October 31 annually, and attempts to outdo her wacky costumes year after year.

This year the gorgeous star dressed as a robot superhero for her party at Lavo in New York, and her impressive outfit with built-in stilts was so bulky and tight she had to practice moving around in it before the party began, although she claims it wasn't difficult once she got the hang of it.

"I practiced a few times ... it's not that hard!" the beauty told Us Magazine. "I can't really bend anything!"

Heidi's outfit was designed by Martin Izquierdo, who also created the famous Victoria's Secret angel wings she wore during her years as an ambassador for the lingerie brand. The star admits her make-up actually took a lot longer than getting dressed, as she was covered in glittery purple.

"I wanted to be like an alien transformer. It took a few hours [to get ready], but I was well-prepared because someone has been building it for me for quite some time, so when the time came, I just put it on. But the make-up, that took a little while longer!" she laughed.

Meanwhile, Heidi's singer husband Seal, 47, opted to disguise himself as comic superhero Silver Surfer. Heidi explained the British musician didn't feel comfortable enough to follow her with the stilts option, preferring to keep his feet firmly on the ground.

"He did not want to be on stilts, so he thought, 'OK instead of height, I'm gonna go wider.' So he wanted to be the Silver Surfer," she added.