The Croque-mitaine is the French version of "the bogeyman".
The bogeyman (also spelled boogyman, bogyman, boogieman, boogey monster) is a legendary ghost-like monster. The bogeyman has no specific appearance and conceptions of the monster can vary drastically even from household to household within the same community; in many cases, he simply has no set appearance in the mind of a child, but is just an amorphous embodiment of terror. Bogeyman can be used metaphorically to denote a person or thing of which someone has an irrational fear. Parents often say that if their child is naughty, the bogeyman will get them, in an effort to make them behave.