There has been a lot of great designs for the Turnip Man and out of all the ones I have seen, my favourite is the one by rinku726.  I just think her design has really captured the essence of the character - the sad smile, the slight hunch in the back etc.  

Here I tried to create a character sheet for animators based on her design and I have incorporated Jacky Dan's idea on the hat XD  Also I did some research on how one could create a pencil sketchy look in a video and I stumbled upon this tutorial for After Effects:  http://ae.tutsplus.com/tutorials/motion-graphics/give-your-video-a-pencil-sketched-look  Unfortunately I do not have AE installed on my current computer so I could only test the filter on still image instead of a video clip and I have included the result of the 2 quick tests I did.