Reader "Greedo" pointed us to an article in The Times (UK) about British influence in Episode I. It reports,

Lewis MacLeod, a Scottish television actor, so impressed Lucas at an audition that his voice and features became the basis of a "loathsome, ugly alien everybody hates", as he put it recently. Star Wars fanatics are now dutifully scouring the Internet for the latest on Sebulba, Mac-Leod's blob-like monster.

This information conflicts with TFN sources claiming that actor Ray Griffiths serves as the voice and CGI reference for Sebulba. Also, Sebulba is not "blob-like" so it's possible that the reporter is mistaken as to which alien Mr MacLeod is playing. (If anyone has information on Lewis MacLeod and work he has done, please let us know.)