Just wait, Lucas will have *Whales* flying around Bespin in the next edition.
Ralph McQuarrie already did some art on this years ago. They're called Aiwas and they fly around Bespin. They were later used by Lucas on Kamino.
McQuarrie's art for them at 1:28 http://www.youtube.com/watch?v=pH9ix8PEM-Y&feature=related