I could write a book on this. My son, almost 5, has a promising career in communication if someone will pay him to create contractions and compound words using only "potty" and unpleasant words. A compound potty word would be something like "peebuttboogerhead". My sister has assured me that this will go away when he's about 12. Only 7 more years to go.
Yesterday, Louis was playing the Bunnytown games on the Playhouse Disney site, and he got to customize his bunny's fur, outfit, accessories, and name. He could have named that bunny Fluffy or John, but he chose something entirely different: