Neither Drawn! nor Monsterosity are “free illustration” sites, however, you can learn a great deal about illustration by studying what’s there.

I’ve been following Drawn! for a couple of years. This multi-author site does an excellent job of showcasing a lot of visual talent across the Internet. It has introduced me to a lot of great illustration sites and online comic books.

Monsterosity seems to be on hold, but there’s an incredible wealth of monster illustrations from Richard Yot. I can only hope the site hasn’t been updated because he’s been busy with work. There are some fabulous monsters there, which will no doubt inspire you in your own work.