Ja'Cen, Overlord of the T'Wnk sat on his throne being serviced by a pink haired breeder. The boy was highly skilled at pleasuring cocks, which was only natural considering that T'Wnk were bred into their castes: White haired Rulers, like Ja'Cen; Blue haired Protectors, like the two well muscled specimens that flanked the Overlord's throne; Black haired Warriors who carried out the Overlord's will; Red haired Scientists that performed the research that drove the T'Wnk Empire; Blonde Servants that did all the jobs that kept the Empire running; and finally the Pink haired Breeders that served as living sex toys for all the other castes.
As the Overlord climaxed and blew his load all over the pink haired boys face and body, Ja'Cen looked over the display of what was soon to the be new T'Wnk homeworld, the planet currently known as Earth. It was nearly perfect for their needs; breathable air, plenty of water, a mostly temperate climate. There was one issue however, Earth was already inhabited by a race called "Humans". Ja'Cen rewarded the Breeder with a headpat and dismissed the pink haired boy, his nude gravid form sashayed away from the throne, Ja'Cen's semen glistening on the swollen belly that contained a child of the Overlord.
The Overlord turned back to his overview of the data on Humans. They were in some ways similar to the T'Wnk, but they had two sexes! Males, which were nearly identical to his species and Females which looked a bit different, with swollen chests and no cocks. Apparently Human females were similar to Breeders in that they were the ones who raised the children. If the T'Wnk were to make this world their new Homeworld then the Humans would have to be dealt with. Fortunately the similarities between Humans and T'Wnk were a huge advantage. It meant that Humans were perfectly suited for Conversion into T'Wnk! In fact the initial phase of Conversion had already begun: the Scientists had deployed thousands of triangular metal monoliths all over Earth, some of which the Humans even discovered and puzzled over. These monoliths took sensor readings to adjust to local conditions and then dispersed into millions of nanites that by now had infused into the bodies of every human on Earth. This would allow the T'Wnk to not only control the Conversion of Humans into T'Wnk but to keep them largely unaware of the entire process. With a bit of luck the people of Earth wouldn't even notice the difference! And on the off chance they did, their new bodies wouldn't be able to resist their new Masters. Their language, their culture; it would all be replaced with that of the T'Wnk Empire.
Down on Earth Ty went to bed with no knowledge of the nanites swimming through every cell in his body, receiving commands to transform the Human boy into the very first T'Wnk on Earth.