Here is a recent character study on the Teenage Mutant Ninja Turtles. If you look at how the turtles were drawn in the original cartoon, they basically all look the same with the exception of the color of their masks and the different types of weapons they carried. Recently I had been given a challenge to draw each character in a way that portrays their personalities. I did so without their weapons to see if people could name each turtle based upon physical features, expressions, and gestures. Hopefully to anyone who is a fan of the turtles, it should be obvious.
Here's a recent digital painting I did for an online contest. The assignment was to create a colossus villain character for players to fight against in a video game. The character had to follow one of six themes. The one I chose was Earth and here was the result... and yes he has a chunk of an entire castle on the end of his chain as a weapon. :)