Guerlais has a wonderfully springy and energetic style, with some of the feeling of good hand-drawn animation art.
His website opens to the portfolio, which is unfortunately a bit vertiginous in that every selection is zoomed when clicked. You can also find many examples of his work on his blog.
Both are in French, with occasional English translations on the blog, but the images, of course, require no translation.
Guerlais has a new book, Les 3 microbes, that from the preview on Amazon.fr, looks to be an absolute treat (images above, bottom three).
Unfortunately there does not appear to be an English language version yet, but I hope there will be one. (You will find more illustrations from the new book on the Shannon Associates sites than on his own site.)