"It is so sweet that he's actually doing this. I've done this many times, doing prosthetics and all of this stuff, so for him to go through this is pretty phenomenal."
Heidi and Tom, 29, arrived at the 'America's Got Talent' judge's annual spooky bash in a large white flower-covered carriage, and even posed on the red carpet with a carriage full of ogre babies, as seen in the movie series.
Previously, the beauty had teased that her costume wouldn't be scary, and would instead be "cute".
She said: "This time it's going to be very cute, It's not gonna be scary; it's going to be very, very cute."
This year marked the 19th anniversary of Heidi's annual Halloween bash
and she admitted her costumes have grown more elaborate over the years
- which can also be risky.
She said: "In the beginning stages, I didn't know about these [prosthetics] professionals yet and I did my own hair and make-up, and I had some people who would help me put the clothes together.
"When you do prosthetics and all of this stuff, I'm always having my fingers and toes crossed that it actually does work out on the day because there was no dress rehearsal.
"Because we can't actually glue all these things down and see if it actually really works. So it's always a bit nerve-wracking for me, too, that it actually does work out in the end. Usually it does, but you just never know until the day comes."
