I checked the databank of starwars.com for an answer and here what i found.......
"Early drafts scripts of A New Hope identified the Emperor as "Cos Dashit", who ruled from the Imperial Throneworld of Alderaan.
When writing Empire & Hope, Ralph McQuarie made the "Cos Dashit" artwork and concept art. "Cos Dashit" originally was a sort of beast who lived in Alderaan then later when A New Hope's script was finalised was to be living in the Imperial City aka Coruscant.....