Black Choker

Black Choker is an accessory.

Source
Black Chokers can be obtained by one of the following methods:
 * Enemy drop:
 * Hunt reward for Devils Cry Curses
 * Hunt rank 6 award
 * Collectible around the world:
 * Costlemark Tower
 * Costlemark Tower maze (Chapter 15)
 * Wiz Chocobo Post (Chapter 15)