See the finished film here ~ LINK ~
There is no way the Prince's head could fit into the Knight's helmet, but I kept the design because I liked it.
References for the Knight's design
The Apprentice/Wizard's design changed the most throughout, mostly during production. In the end I made him loopier, with less angles, and his outfit was a bit different.
The Hopgoblin's design also changed a bit as I went along, mostly in color design. He was may favorite to design and animate.
References for the design of the various settings in the film. Early on in the pre-production phase I didn't have any backgrounds or concept art for the settings, so I used a lot of pictures from various artbooks (Tales from Earthsea, Mulan, and How To Train Your Dragon).