Why some people are called "Black Cats" in police department ?

I don't think cats are that wild to attack or safe guard anyone.. So, Why they aren't are being called as "Black Tigers", "Black Lions" "Black cheetahs", "Black elephants"...or even "Black dogs"..... lol cat is a pet animal though which is considered as... show more I don't think cats are that wild to attack or safe guard anyone.. So, Why they aren't are being called as "Black Tigers", "Black Lions" "Black cheetahs", "Black elephants"...or even "Black dogs".....

lol cat is a pet animal though which is considered as wild animal at this view...
Update: Also tell me Why specifically chosen black color...??
11 answers 11