I can answer your question!!
for those that don't know, Lucas wanted to make a Flash Gordon movie completely based on Alex Raymond's comic strip series from 1934-1943. However, he was unable to secure the rights, so he created his own universe based on Flash Gordon.
Taun-tauns were designed after the beaked snow-birds from the ice-planet sequence in Flash Gordon in 1938-1939.
I used to own the original art to this one.