The R Skull is a simple skull that is negative sized.
This skull was first crafted to be used as a weapon in the first negative dimensions war, However, it was then abandoned for almost 400,000,000 years until someone by the name of Ael Onpet came across it. He found it using a special tool that saw into the negative dimensions. This skull is now used as the protector of The Bocks.
The way this skull works is it is in the centre of The Bocks and it protects it by shooting out slimy spider-web-like grey stuff to the sides to catch anything trying to invade it. This is actually very effective, with zero things managing to invade The Bocks.
This skull is named the skull because it kind of looks like a skull, but it is not a skull. It is grey and is shaped like a potato and has some grey dots on one side, but only three on the front. People thought it looked like a skull, and it was named "R" because it was the name of the date that Ael discovered it in negative dimensional terms.