I did this mashup drawing as a demo for my cartooning students. I'm doing a series of drawings with cartoon characters in Halloween costumes for my class. This Spongebob Squarepants drawing was done digitally using my wacom tablet in the GIMP and inkscape. Process is below -ROUGH SKETCH
After I finished, I decided to add some color to the holding lines, but I'm not thrilled with the results. I'll have to devise a better method for color holds.