At the time I was just throwing words together, but since then I’ve developed them into being developed by a colony of humans who are into grotesque levels of gene modification in pursuit to maximum physical prowess. They have side projects like the raptors which they sell.
Because of poor control procedures, the raptors have spread. The colony would sell them to whoever was willing to pay, and inevitably some of the customers lost control, meaning the raptors have become a nuisance on various planets.