Looking into the art styles of Backwater Gospel in more depth I have taken to the styles well and look to incorporate the style into my own working. These are the planes from the character designs for the Tramp, separate planes that have image planes UV mapped to them and then simply curved round to sculpt the head.
With the front plane there was a grid that displayed all of the tessellation and it seems like the modeling has been done upwards to fill out and form the face. Then it seems like plane is curved from the edges to form round the then would be face.
Then they simply marry up the planes and from what I could derive from it is that the back of the head (hair plane) isn't warped round and is instead pushed up to make a flat back of the skull.
All of the head assets are very low poly with low tessellation, with most of the detail actually coming from the textures instead of the detail made from the model. The mouths are interchangeable and marry up to the facial expressions made by the character.