This is another one of those art things like my SPIRALIZR and my snow project, but this time, you make art with Scratch's mascot, the scratch cat. He'll follow your mouse and stamp everywhere he goes, but if you have to make him stop stamping for any reason, press x, and when you want him to start stamping again, press y. You can move the Color Change: slider to change how fast the scratch cat changes color. Press the up and down arrows to control size.
I got most of the code from Coding Projects in Scratch, but I still added some things that weren't included.
