Here's the classic silver screen Frankenstein mask. It doesn't look comfy, but it looks so cool it's probably worth the sweatiness and discomfort.
Here's a goofy comedic looking Frankenstein mask with exaggerated features.
I actually find this full head Frankenstein mask very creepy. I'm not sure how I would cope if someone knocked on my door wearing this.
This latex Frankenstein mask is really intense. It comes down to cover part of your chest, too.
I can't stop laughing at this Frankenstein mask with hair. It's just so.. spiky and weird looking!
Also, if your Frankenstein needs a bride, here's a goofy inflatable Bride of Frankenstein hat.