amfAR Milano 2015 - Red Carpet
Credit: Venturelli/Getty for amfAR

Supermodel Heidi Klum isn't afraid of looking, well ... not pretty. The 42-year-old is known for her over-the-top Halloween costumes, and it seems like 2015 will be no different.

Klum hinted at this year's getup on Instagram with a behind-the-scenes look at the team at Prosthetic Renaissance while they were hard at work on her new costume. However, the photos leave us with more questions than answers. Why is she wearing a full body cast? And what is that blue slime they're covering her in? Has she lost her mind? And more importantly, what on Earth is she going to be?

What we do know is that whatever she's got planned is going to be epic—and hopefully worth the effort. Guess we'll have to wait until Halloween to find out.

Watch and see her mysterious costume take shape in the below videos and photos: