The monstrosity had been created by Deathwing's son, Nefarian. Nefarian had tried to create a new dragonflight that would combine the powers of all five of the other flights. The experiments were considered failures as many whelps had died before hatching or were deformed in many ways. Chromatus was Nefarian's final experiment. Chromatus exemplified the pinnacle of all Nefarian had learned through his various experiments, but Nefarian was slain before he could give Chromatus the spark of life. Years later the Twilights Cultists brought the body of Chromatus all the way to Northrend, knowing that they needed vast stores of arcane energy to give him the spark of life.