If it is in the back of neck, go to a chiropractor. More than likely its a sore muscle.
The skull
The root word "cranio" pertains to the skull or cranium. It is commonly used in medical terminologies related to the head and skull.
If the skull is carrying the dagger in it's mouth - it is related to secret business.
Check the related links below. Look up Famine Skull on Youtube.
There are a number of retailers from whom skull rings can be purchased. These include the online retailers Skull Rings, Skull Is and Crazy Pig Designs.
No
The skull by itself means the mockery of death. The hearts could be part of the skull's decoration, as to be less frightening: a skull with empty eye sockets is a bit horrifying.
Please specify which GAME your playing.
The black wither skull is the normal wither skull, however the blue wither skull is much more devastating to the terrain around it. The black wither is much faster, meanwhile the blue wither skull is slower. Building a shelter against a blue wither skull will not work, as it can break through obsidian. The shots fired from a blue wither go on forever until it hits something, so the blue wither could unintentionally hit something else. Read more on the wiki in the related links below.
See related links.
The skull is used to protect the brain. Lets say you bumped your head. If you did not have a skull, the brain could be severally damaged. But, if you have a skull, the brain wouldn't get damaged. When your a baby, the skull hasn't been fully developed so that is why people are so careful handling their babies.
No. The tradition came from Calico Jack's flag, which was called the Jolly Roger with the traditional skull and crossbones, but the name went on to represent all flags, regardless of what they actually portrayed on them.