Did you know you can plot Darth Vader on WolframAlpha?! There are many more fun curves! A dalek perhaps or Batman?!
If those equations are a bit much you could try something simpler using the Desmos graphing calculator; for example look at Alec Schultz’s PacMan.
To experiment click here or on the image above to see how this was created and experiment yourself. (In case you see a blank graph screen just reload the page).
Desmos have a whole gallery to inspire you! You can of course get very sophisticated. Look at this lovely evening by Petr Feidler! Note the use of inequalities for shading and the slider!