A monkey is outfitted with a cane and a mask and measured. The simian was also briefly considered for walking shots of Minch-Yoda that would have been impossible to execute with a puppet.
A great piece about the creation of Chewbacca (it turns out it’s a little more than George’s dog, Indiana):
Chewbacca, the character, also started his life in the rough draft (May 1974) as a kind of barbarian alien prince on the jungle planet of Yavin:
…The eight foot Chewbacca, who resembles a huge, grey bushbaby with fierce baboon-like fang…
The article has great background on the development of Chewie’s appearance and story arc (or lack of unless you subscribe to an alternative interpretation) along with great concept art and costume images.
I think my favourite image is this one of Ralph McQuarrie’s where a Storm Trooper is wielding a lightsaber:
Logorama is a 16-minute animated film written and directed by H5/ François Alaux, Hervé de Crécy and Ludovic Houplain, and produced by Autour de Minuit. The film depicts events in a stylized Los Angeles, and is told entirely through the use of more than 2,500 contemporary and historical logos and mascots. The film won the Prix Kodak at the 2009 Cannes Film Festival and the Academy Award for Best Animated Short Film at the 82nd Academy Awards.