Roosters are terrific subjects for drawings and paintings and even graffiti. While they are "just chickens", roosters have a lot of emotional connections to fighting, dominance, flashiness and pride. Their long flowing feathers are fun to reproduce with magic markers or any paint, and the way they can fly and fight and move like lighting gives you enormous opportunities to depicting speed and flashing feathers in your work.
Of course, some people take a totally different tack with their roosters. They use very simple, staid rooster designs for decorating country walls with stencils, or to decorate almost anything with a country theme. If you are wondering how to show the difference between a hen and a rooster with a simplified image like a stencil, make the roosters just a bit taller, with very slightly longer necks (it makes them look like they are strutting), and add the little red comb on the top of their head and under their beak. Everyone will know your chicken is a rooster chicken, not a hen.