Krayt Dragon

Nearly 150 feet long, krayt dragons (CRATE DRAG-uns) can live to be up to 100 years old, and weigh over two tons. On top of their colossal dimensions, their teeth and spines secrete fatal venom. This carnivourous, reptilian, nonsentient species was made up of two species, the first, the canyon krayt dragon, possessed the aforementioned size. The second species, however, was much bigger and much less common: this krayt can measure over 300 feet, and needs all ten legs to support all that weight. C-3P0 walked past a greater krayt dragon spine and skull at the beginning of A New Hope, after he separated with R2-D2, who insisted upon going another way. Greater krayt dragons usually hunt sarlaccs and banthas, and, like all other krayt dragons, they develop a pearl in their gizzard; pearls from greaters are bigger and thus more valuable than those from canyon krayts. These dragon pearls can also be used by Jedi, after shaped, as focusing crystals--the crystals that focus the blade in a lightsaber. The weaknesses of krayts are few, but undeniably there: krayts have trouble with two-dimensional images, and sometimes react to shadows and the like. Also, a shot from a skilled gunman can, through the weak sinus cavity, reach the brain, killing the dragon instantly. Before a Sandperson could be accepted as an adult in the tribe, they were abandoned in the desert and not allowed back in until they had killed a krayt. Also, Jawas brave and successful enough to obtain krayt bones, which they believed to possess magical properties, were highly regarded among their people. The skeleton used in the filming of A New Hope was left at the site after the scene was shot, and when the crew for Attack of the Clones visited the Tunisian Desert, where they had left the fake skeleton, it was still there. Isn't that cool?

The Rule of Two

The Rule of Two is the unwritten code that states that, "Always two, there are--a Master and an apprentice," as Yoda observed.

Remember: power alone is not enough. Patience. Cunning. Secrecy. These are the tools we will use to bring down the Jedi. The Sith are only two now--one Master and one apprentice. There will be no others.
This Darth Bane said to his apprentice Zannah.

The Sith Code is as follows:
Peace is a lie; there is only passion.
Through passion, I gain strength.
Through strength, I gain power.
Through power, I gain victory.
Through victory, my chains are broken.
The Force shall free me.

The users of the Dark side of the Force can undergo serious physical changes, including the change of the eyes from their normal color to an acid yellow. The skin, as in Palpatine's case, can also become gray and overly wrinkled. But these users can change between their original appearance and their current appearance, as Palpatine and Anakin have done.

Utapau

Utapau (OO-tuh-POW), visited in Revenge of the Sith, is a sinkhole-ridden planet that lies approximately 51,000 lightyears from the Core, inhabited by the Utai and the Pau'ans, together called the Utapauns. Orbiting a solitary sun, unlike Tatooine, and orbited by nine moons, the core of this planet is molten metal, and less than a percent of Utapau's surface is covered in water. The water that once covered more of the planet leaked into underground caverns that were at one time magma chambers. This leakage caused the sinkholes that now dot the planet in abundance. In times ridden with conflict, this planet struggled to retain neutrality. Of the two races of near-humans that inhabit this Outer Rim planet, the tall, gray-skinned Pau'ans make up only about a third of Utapau's population; they assumed the more government-associated possitions in the Utapaun society, while the Utai served as janitors and lion tamers for varactyls and their dactillion relatives, both referred to as dragonmounts. The Pau'ans remained at the surface, and the Utai tended to live underground; but thanks to the former, the two now live in harmony, their cities built into the sides of the magnificent sinkholes. The native creatures here are the aforementioned dragonmounts, and the nos monster, a carnivorous, water-dwelling reptile.