Serak the Preparer is a Rigellian.
A cohort of Kang and Kodos, he made the Simpson family dinner while on their way to their home planet. He was also mentioned in the Bart Simpson Comic "Cooking with Kang & Kodos". In Treehouse of Horror, Serak comments that in order to pronounce his name correctly, the speaker's tongue would need to be pulled out.
Behind the Laughter
The name Serak was obviously adopted from Star Trek's character Sarek (the father of Spock), just as the name Kang and Kodos are also names taken from the original Star Trek.