crazy like a fox vs ulterior

crazy like a fox

adj
  • Behaving in a foolish, frivolous, or uncomprehending manner as a ruse for concealing clever deeds or deeper intentions. 

ulterior

adj
  • Being intentionally concealed so as to deceive. 

  • Situated beyond, or on the farther side. 

  • Beyond what is obvious or evident. 

How often have the words crazy like a fox and ulterior occurred in a corpus of books? (source: Google Ngram Viewer )