A cartoonist is someone who draws cartoons. That can mean a funny picture in a newspaper, a comic strip with the same faces every week, a sharp political drawing that laughs at leaders, or the pictures that later become an animated film. In English, cartoon is wider than 卡通 in Taiwan: it is not only children's animation. A newspaper artist and a film animator can both be called cartoonists, though people who make moving films often prefer animator. The ending -ist just means a person who does this. It is an ordinary job-word — not slang, not very formal.