On this page ...
https://cgcookie.com/courses/short-film-character-production
... the href on "See how Tim illustrated Piero!" doesn't point to where the course now resides. It should point here:
https://cgcookie.com/courses/piero-animated-character-concept
(but it points here instead: https://cgcookie.com/course/piero-concept-art-course)
Cheers!