Setting
The Beast is a living universe. It is dyed a dark green and dark red in alternating patterns, in a vaguely plaid pattern. If one looks closely, they will note it is because of streams of chorophyll and blood flowing through the universe, like veins.
The Beast is also intelligent. At the center of the universe is it's brain. If one would dare try to harm The Beast, it's nervous system would alert it and it would lash out with cosmic radiation at the foe, as well as the foe earning the ire of Roothor.
Of course, these were not it's only protection. Roothor also created Dryads, beings that acted like blood cells; ferrying radioactive nutrition to the Beast, as well as protecting it from harm. They were only semi-intelligent, little more than automatons.