5. Wookies - Star Wars Episode II: Attack Of The Clones
Every character outside of the central trio who appeared in all three films in the original Star Wars trilogy (Obi-Wan, Anakin, C-3PO and R2-D2) also popped up in every prequel. In the fact the latter duo will likely make it through the sequels alive (heck, Obi and Ani will probably pop up as blue Force ghosts). With the odd way the same characters seems to be linked to every key galactic event (a phenomenon known as merchandising) this naturally means few characters miss an instalment. Of course, if you watch the series in in-world chronological order then there are a couple of these - both the Yoda and the Emperor sit A New Hope out - but as at the time they hadn't been conceived of or were purposely kept off screen to include them here seems against my initially strict rules. Fret not - Star Wars can be on this list. Wookies as a species are most certainly Star Wars essential. After Yodalings (not the Lucasfilm approved name) the most famous species from the galaxy far, far away, wookies were gallantly represented by Chewbacca in the originals and made their long awaited appearance en masse in Revenge Of The Sith. But with a small cameo in the Senate during The Phantom Menace, this makes Episode II the only movie to not pay tribute to the walking carpets. Who knows if Episode VII will continue the trend of wookie cameos; in the Expanded Universe timeline Chewbacca is dead by the time the film starts.