Pudding basin (small) for moulding head
Plasticine to make face over pudding basin
Waterproof container large enough to hold face for moulding (I used a cardboard box lined with plastic bags)
Fibreglass and resin, or papier mache, (or anything you can make strong enough to take mechanisms which go inside)
Epoxy resin, glue, or anything else you can find which will stick what you're using to make it together
Drainpipe/guttering/roll of cardboard or tube of suitable diameter to make neck
Paint (ideally approximately flesh coloured) METHOD
I initially considered making the head from papier mache as per the blueprints, but decided that if he was to survive in a house with three kids crashing about I would need to make it out of fibreglass and resin.
To make the mould for the face, I took a small pudding basin, slightly smaller than a young child's head, and got our eldest son to built a face over the outside using plasticine. I wanted the features to be strongly pronounced, but obviously it can look like whatever you want it to.
To make it easier for ourselves we made the lip-line straight line horizontally, and the jowls straight down and parallel to make it easier to cut away the chin section when it was cast.
When we were happy with the face, I mixed up some plaster and poured it into a box lined with plastic bags (if you have a container large enough to hold a pudding basin covered with plasticine you can use that, or anything else you have to hand). I gently pushed the face, nose first, into the plaster, let it set and then poured more in, about a litre at a time, until the face was submerged in set plaster up to the level of the top of the bowl.
When it was fully set (I left it for about a week), I poured some boiling water into the pudding basin and left it for a couple of minutes to warm up the plasticine to make the demoulding easier. The water was poured away, and I waited for the bowl to cool down to the point where I could get my hands in to prise it out.
BE VERY CAREFUL DOING THIS, BOILING WATER IS HOT
The bowl came out quite easily, I pulled the plasticine out as carefully as possible so that I could put it back over the bowl, cut away the features and repeated the above process to make the back of the head (although I waited until I'd made the fibreglass face so that I could mould the edge of the plasticine around the edge of the face to make sure they join together as closely as possible).
The face was made by fibreglassing into the plaster mould. I raised the eye sockets inside the mould to make it easier to glass around them, saving having to cut the eye holes out later. (If I were doing it again I would also think about ways of casting the chin seperately).
I'm not going to describe the process of fibreglassing here, there are already some excellent Instructables which go into that elsewhere on the site, have a look at http://www.instructables.com/id/How-to-Fiberglass/
I rubbed a good thick coat of wax into the mould before splodging the resin and mat into it. Try to get it as even inside as possible, with no sharp pointy bits - you'll be doing some fairly fiddly work in what will be quite a confined space before long, and you don't want to be jabbing or cutting yourself when operating on your creation.When the glass was dry I demoulded it as carefully as I could to keep the mould intact for making the back of the head, and then rubbed and sanded off the bits of plaster which had stuck to it. There were a few air bubbles which I filled with little bits of epoxy.
For the back of the head, I filled out the features in the mould with dollops of plaster, rubbed around with a rag to get it fairly smooth, and this time I placed the lid of a jam jar - wide enough in diameter for one of my hands to pass through - into the plaster, leaving most of its height standing out enough to give me something to fibreglass around leaving a hole in the back of the head large enough to enable any future maintenance on the moving parts.
I would recommend leaving the head in two parts until you've got the mouth and eyes fixed in and working (see next steps).
The neck was made by fibreglassing over two short lengths of guttering pipe, which were later stuck together and to the head with epoxy putty (when all of the mechanisms in the head were in place and working).
Finally (for the main features), the ears were made out of plasticine, cast in plaster, then positives made in P40 fibreglass car body filler, and stuck onto the head with epoxy putty.
I made a cover for the hole in the back of the head from P40, using the plastic cap of a yoghurt carton of similar size to the hole, which would later be fixed into place with a couple of small bolts into nuts held in place on the head, again with epoxy putty.
Finally. I filled the roughest areas of the face with epoxy, and sprayed the head with pink paint.