"Khan" from proto-Sanskrit and comes into virtually all Indo-European languages as "King" or the equivalent. Therefore "Guest King". du also proto-Sanskrit and has remained virtually unchanged but is usually repeated, at least in the English ("kakon" in the Greek) and is rendered "Doo-Doo" Therefore it is "Geust King Doo-Doo" or Guest King doing Doo-Doo or more generally doing whatever you do do.

As for being without a cookie, that reminds me of a little story my family doctor of many years (many years ago) told me. A man came to him complaining of a tapeworm which examination confirmed. The good doctor ordered him to drink one glass of milk and eat one cookie for each meal for a week and then return to the office early on the eighth day and to bring a carton of milk with him. This the man did and then the doctor sat the man on the exam table and had him drink the carton of milk. Very shortly the tapeworm crawled up the man's throat and stuck his head out of the man's mouth and demanded "Where's my cookie?" whereupon the doctor grabbed the parasite and pulled it the rest of the way out of the man's gullet. Ain't modern medical science something?