A few years ago I taught little kids in Japan. One activity they loved was "colouring-in time-o" (practically every Japanese word ends with a vowel).
Every week I'd draw a variety of monsters and robots for them to colour in. This little fella is a more fleshed out version of my simple line drawings.
As a footnote, one of my students entered theirs into a national colouring in competition (how cool is that! a NATIONAL colouring in comp), and came pretty close to winning. After this exposure, it was used (and maybe still is used) by hundreds of elementary schools all over Japan.