This is a cartoon human "skull" with a pair of crossed bones behind it, which usually appear on the "pirate flag" and poison bottle, indicating that this is a dangerous ship, a dangerous material, with a certain mysterious and horrible color.
In addition to the icons of emojidex platform, the cross-placed bones are located below the skull, and in the icons of other platforms, the cross-placed bones are located behind the skull. This emoticon is usually popular around Halloween, which is used to represent death or various dangerous thoughts, and can also represent various pirate characters or mascots.