fee-faw-fum

from The Collaborative International Dictionary of English v.0.48

Fee-faw-fum \Fee`-faw`-fum"\, n.
   A nonsensical exclamation attributed to giants and ogres;
   hence, any expression calculated to impose upon the timid and
   ignorant. "Impudent fee-faw-fums." --J. H. Newman.
   [1913 Webster]