The Green Slime, as its nickname suggests, was originally an amorphous green-colored sludge-like lifeform which was discovered inhabiting the asteroid Flora, which was moving towards the Earth. Strangely for such a celestial body, the asteroid seemed to have Earth-like gravity and shallow water puddles scattered on its surface, alongside which the green creatures grew like patches of seaweed. They showed limited mobility, inflating and deflating rhythmically and being able to crawl around the ground, and also had a faint phosphorescent glow. While Flora has been since destroyed by explosives planted by a team of astronauts led by Commander Jack Rankin to prevent collision with Earth, a small sample of one of the creatures' tissue was accidentally brought on board the space station UNSC Gam