Just a couple of examples of work created in Illustrator for various uses, the wolf is part of a comic book cover I created for a course, the eagle is part of a logo I created for a website. Both were trace images and partial freehand, the wolf was a composite of quite a few photos put together in Photoshop, and imported into Illustrator to draw the final images. The jaguar was an illustration I worked on for myself. It's from an image in a calander and I wanted to see if I could pull it off in Illustrator, it took me about a week to complete.
Free hand illustration:
This was a course project, a 5 panel metamorphosis. This was created in colored pencil.