So, by act of Random Omnipotent Being (ROB), about 50 or so Tribbles...
Have ended up on the planet Ach-To - specifically, the island that Luke was hiding out on. During their stay, the Tribbles run afoul of some of Ach-To's most well-known animals, the Porgs:
For reasons known only to animals, the two species have now entered a direct competition for resources. Which one comes out on top? Tribbles, or Porgs?