Here is my whole set of paper mache Octonaut heads. They have been modeled on giant punch balloons (hence their size), they are all hung with string.
All you need is newspaper, flour and water paste and a few other bits and pieces of junk (empty plastic bottles, paper plates and bowls).
I started with Shellington. Basic shape, done a few layers at a time. Cut a polystyrene bowl in half and placed on each side for ears, papered into position. The hat was an old cereal box which I folded around and then another upturned bowl put inside. The hair and nose balls are just screwed up molded newspaper.
He then ended up looking like this: 
To place the string inside each head (and take the balloon out) I put my hand in the hole to one side. I'd threaded the string through an old lid of some sort to give it more strength inside the head too, that helps support the weight when hanging. Then just paper over the hole. Below is Captain Barnacles getting his string and Captain Barnacles and Peso prior to painting.
Kwazii had a minor drying injury though, the weight of the wet paper made his head cave in a little. He needed a bit of surgery the next day to push out (luckily I had to put his string in anyway).
I did the easy characters first, Shellington, Barnacles, Peso and Kwazii. I wasn't going to do the others but then I had the spare balloons, the time and the free papers kept falling on the mat.
I did Tweak first, making her ears from a 2ltr Coke bottle cut in half lengthways, you also need to cut into the head to secure it slightly with this way too or else you'd never get it to stay up whilst drying. As I added the paper to the bottle the weight dragged them outwards, so I had to bind them with string while they dried.
For Dashi I cut a milk carton in half lengthways and masking taped it to her form.
Professor Inkling was simple, some cardboard (an old cat food container) cut to the shape of his ears and cut into the head and papered stiff. The only other extras for him were a collar (although they all have collars I thought his was most important, more defining in his body shape). I added a Pringles lid to the eye for his monacle and stuck a short piece of string between it and the collar.
Tunip was last but not least. He was formed from a large normal balloon, as he is smaller than the others. His limbs were just pieces of an old cereal box cut into shape and papered into place. His green top was more complicated, it looked great at first but the weight of the paper made it sag a little.
So now, I am the proud owner of a set of Octonauts. Not sure what to do with them. I did originally consider wearing them as a head, like Frank Sidebottom but I'm not sure how they'd stay on. I think I may put them in the loft and save and hope that Jemima likes them in the summer and they may come down for her birthday party too.
