Location: Wherever there are Predator aliens
Threat Assessment: 3. Fast. Deadly. Hard to kill. They have lots of teeth, claws and horns.
Limitations: They are domesticated animals under control of the Predators. Enough firepower will kill one. Beastial intelligence.
Personal note: Some critics said that these dogs couldn't have evolved naturally because their horns would get in the way of feeding. To this I say, "duh," because we humans have taken a perfectly good natural predator (the wolf) and turned it through breeding into a pug which has the survivablity in the wild of a soap fish. It makes perfect sense for the gung ho predator aliens to take some nasty beast and breed it to outlandish nastiness.