I've been working to put together a Fire-Swallower Side Show act for an upcoming Carnival haunt theme. I don't have the whole prop put together yet but here's how I'm achieving the head for him. Someone asked about something like this on one of the forum threads so thought I would share my solution for my prop head.
After a lot of searching for just the right mask, I decided on the Cacophony Gnarly latex mask which is currently available on a number of store sites. Runs around $25-30 new. It has five open mouths around the head. The ones on the side might be able to be covered by a clown wig and the eyes with a masquerade mask; another solution for the eye and ear area would be to create a fabric blindfold that will cover both areas (all four mouths). To coverup the neck area I thought maybe one of those frilly gathered clown collars might do the trick. Of course this is a Side Show Act so this mask might just fit in with the weird and unusual look of the acts anyway! The mask will be positioned on the prop with the face upwards. This will allow the flaming torch light to be in a vertical position so the flame will flicker upwards from his mouth.
For the Fire aspect of the prop, I went with one of the Flaming Torch Lights (IN-16/552, $3.75) from Oriental Trading. Runs on 2 AA batteries. The torch is 7-1/2 inches long and will fit inside the mask without any modification.
Nightview of Fire-Swallower:
The mask, which can be used for an animated sword-swallower act too, will need to be modified by cutting the mouth area to make it larger. Just use your scissors and lengthen the opening.
The fabric flame will need to be trimmed to fit inside the new mouth opening and have room to flow.
Here's some photos of the flame coming out of the mask mouth and how the torch fits in the mask.