Astral Saga: Stars of Strife
The home world of the junkrats once had a purple moon. However, it was stuck between the temporal and the arcane realms. The Ancients attempted to fully remove it from the Arcane Realm, but in so doing destroyed it. The shards of this moon formed a ring in orbit of the planet. Every once in a while, crystalline moonshards would fall to the surface of the planet. These were emitting a small amount of Arcane Energy, which, over tens of thousands of years, made its way into the genetic code of all life on that world. In many cases, it had little effect. In the Junkrats, however, it left a mark that would remain forever.
Each Junkrat is born with a gift, a sort of magical talent. Most of them are very powerful, and all are seemingly random. For some it might be that they have some ability to divine omens, while another might be able to ingest poisons with no ill effect. Really, they are just completely random. The only consistency is that no parents will ever see duplicate powers among their children. Between generations, maybe, but not among siblings.
Technologically, the junkrats achieved a fairly advanced level of industry on their own, but never developed digital technology. However, due to their extreme reproduction rates, they were suffering an overpopulation epidemic. They were able to develop some spacecraft, but nothing all that impressive. However, it was enough to get the attention of the Sanctarchy of Balaat, who elevated them to a starfaring civilization. Without the restrictions of having only the resources of a single planet, their population increased exponentially. Now, they are literally everywhere. In some cases this is a burden. In others however, its nice to have such an abundant source of cheap labor.
As for their reproduction rate, the Junkrats reach adulthood and begin to reproduce at around ten years. The average Junkrat female will bear, on average, 4 litters, of 4 children, between the ages of 10 and 20. Gestation is only 15 weeks. Most Junkrats live to their forties, with very few living past 50.
So, it’s common for a Junkrat to have over 200 grandchildren by the time they’re forty years old. Yikes.