The Plodex are an alien race from the distant reaches of space. About 50,000 years ago, having realized that conquering the universe by traditional means - flying to a planet, conquering it and moving on to the next - took them too long, the alien species called the Plodex came up with a different strategy. They built special colonization ships designed to carry thousands of Plodex eggs held in suspended animation. These ships were sent to numerous primitive planets still in the early phases of their development, some of them so far away from Plodex space that the journey took hundreds, if not thousands, of years. Upon arriving at their intended destination, the ships were programmed to land in the most uninhabitable region of the planet where it would draw from the planet’s resources and transform itself into a huge underground complex. Once completed, the complex would send out a summons call to the planet’s inhabitants. Only the most dominant life-form would be capable of surviving the trip to the complex. These unfortunate creatures were then studied and dissected, down to their molecular make-up, so that the stored Plodex egg-pairs could be genetically imprinted with the traits of this dominant life-form. Once this process was complete, the complex would eject the egg-pairs, distributing them across the planet. While not all of the Plodex hybrids would survive their hatching or find their mate to breed, the sheer number released upon the planet would ensure that the Plodex would outnumber all other life-forms of the planet.
The same would have happened on Earth, if one of the colony ship’s drive units had not exploded after its ten thousand year trip through space. The craft arrived on Earth but crashed down in the Arctic region. The ship’s systems were heavily damaged by the impact and its egg-pairs were ejected prematurely, before they had been genetically programmed. Those eggs that weren’t destroyed were unable to hatch because the alien infants inside were still without a proper shape. Over the centuries, the remaining eggs dried out or were destroyed by other means. The Plodex invasion of Earth had failed... or so it seemed.