Mannequins

Mannequins are found only in Call of Duty: Black Ops, on the Multiplayer map; Nuketown.

Call of Duty: Black Ops
On the multiplayer map Nuketown, mannequins are found in random locations all over the map, in and out of the map's boundaries. A mannequin's head and arms can be removed by any means, gunshot, knife or otherwise.

Trivia

 * If all of the Mannequins heads are shot off wihin the first 15 seconds of the match beginning, the Rolling Stones "Sympathy for the Devil" will play over the loudspeakers.
 * Rarely, a mannequin will spawn without a head, or arms.
 * Mannequins can also be found inside of the school bus, however these mannequins do not need to have their heads removed for the song to play.
 * If a mannequin's head is shot off with a crossbow, ballistic knife, or semtex, the mannequin's head will fly off, however the arrow, knife, or Semtex, will still be where it was inside of the Mannequin's head.
 * The mannequin seen at the end, during the nuke, and during the after action report, is located inside of the yellow house, and cannot be found during the match, however, it is visible via spectate or by standing in the yard of the yellow house on the very far right.
 * Rarely, when attempting to shoot the head off of a mannequin, it will be indestructable and the head will not come off.
 * In the house similar to the Brady Bunch home, two mannequins can be seen out of the window, and they appear to be holding hands, visible only if in theater mode or spectating.