I find it surprising that there is more than one joke of the following
type, but here are three:
Q: What is Batman's full name?
A: Nananananananananananananananana BATMAN!
Q: What did the Pink Panther say when he stepped on an ant?
A: Dead ant. Dead ant. Dead ant dead ant dead ant...
Q: Where does the Lone Ranger take his trash?
A: To the dump, to the dump, to the dump dump dump…
[ Addendum: Dave Long sent me another! ]