These are what are called thumbnail drawings. Usually, they're miniature drawing practices to test color, lighting, shadowing, shapes, etc, for a final drawing. They're supposed to be quick and small, basically miniature drafts or storyboards. Today I did these not for a final drawing, but for quick small practices. That way it's not so big where I take more time doing them and I time myself to keep them quick and loose. I actually cleaned these up more than needed, it would have been better to not spend that extra time tho... but I couldn't help myself, hehe.
I played with color. I tried picking colors as quickly as possible and adding them "lazily" rather than refining everything. You can see I copied some of them so they're the same character but different colors. I played around with different expressions, characters and even species of mice.
So enjoy this thumbnail practice of mice!