Here's some sketches for The Grim Adventues of Billy & Mandy. It's a smartly well-written show and I can highly recommend getting the first season on DVD. It was written for two audiences: adults and kids, and there are things that will make an adult chuckle while a kid will miss it altogether. I have had parents tell me that they don't let their little ones watch it though since it is edgier than the other cartoons on Cartoon Network around that time slot.
The Grim Reaper is my favorite of this series and he's a very simple design. As I posted before, the simplier the design the better the results. The more detail a character has, the more time it takes to draw it out many times over for a job. You have to design your characters so that you can draw them over and over without getting bored of them. That's a great sign if your design is working. I'll post more Grim art tomorrow!