Whom Christie called "a little creep" (6)
I believe the answer is:
poirot
(Other definitions for poirot that I've seen before include "... and her male one" , "Hercule -, detective (Agatha Christie)" , "Hercule . . . . . ., Agatha Christie's detective" , "Agatha Christie's Belgian detective" , "10 [SLEUTH]" .)