Every animator's nightmare is the crowd scene. Every cartoon "writer"'s favorite word is "crowd". It takes half a second and no creativity to type the word and at least an hour or two to draw one frame of one crowd - let alone having the horror of animating 12 0r 24 frames of crowds for every second of film.
If you HAVE to draw a crowd, here are some tips on how to make one read clearly and look interesting.
Milt Gross is an amazing designer. Most comic artists, even great ones like Jack Kirby draw just one basic face and body type over and over again-especially in crowd scenes. Who can blame them? In this Gross crowd, every lady, while all following a unified line of action, is a completely different design. Invention just flowed out of this guy's pen.