Heidi Klum had wanted to be a "super-ugly" Medusa for "quite some time"

She told E! News: "I've been thinking about Medusa for quite some time, because I've seen over the years obviously many, many Medusas, and I thought, You know, one day I'm going to try my own...

"I really wanted to have snakes that were moving, a super-ugly, super-scary face, really ugly teeth, and to be like a really long rattlesnake."

Heidi's husband, Tom Kaulitz, dressed as a warrior she had turned into stone, and the pair revealed they had spent five months working on their outfits, before taking 10 hours to get ready on Friday.

Heidi said: "Everything is hand-painted. About 15 people have been working on this, and I think they did a fantastic job."

For Tom, his challenge this year is to find a costume to complement his 52-year-old wife's choice.

He said: "This year wasn't that difficult, but sometimes it is. Last year we did E.T., for example, it was difficult. Like, OK, are we going to be both E.T. or one female version? I always have to come up with something that matches.

"[This year] there's not much I could do other than being the man who got into stone. So that's me and I think they did an amazing job."

Heidi noted: "You still look like you."

Despite their elaborate transformations, Tom, 36, told People magazine he thought Heidi looked "sexy".

And she said: "I think he looks super hot."

Heidi - who has Leni, 21, Henry, 20, Johan, 18, and Lou, 16, with ex-husband Seal - teased her costume at the beginning of October.

Sharing a photo of a 3D mould of her face on Instagram on 1 October, she wrote: "This is just the beginning."

Last year, Tom and Heidi dressed as E.Ts, with their outfits taking over a year to produce.

The Tokio Hotel rocker told E! News at the time: "It took a whole team of amazing people. And lots of planning."

Heidi added: "We started at 10 a.m. this morning. We just got ready, we just came down."