There's an episode of South Park that featured the Prophet Mohamed (Super Best Friends) that was uncontroversial when it aired, but now you can't get it anywhere. They did a very good bit about it in "Cartoon Wars". https://en.wikipedia.org/wiki/Cartoon_Wars_Part_I (They deserve like a Pulitzer Prize or something for CW, it's genius.)
It's not illegal to depict the Prophet, it's religious courtesy. (Also, it might interfere with profit (no pun intended.))