I did this as warm up today. It's a weekly exercise for a group I joined on DeviantArt called Design-A-Character. Each month there will be a different challenge that goes throughout the month, with variants every week. This month's is "Shape Challenge"- every Monday a new set of shapes are put up and the exercise is to create characters with them.
This is very similar to a game I played with my friends as a kid. It's pretty fun to get back to it.