Hell-hound

The Hell-hounds are a canine-like species domesticated by the Yautja for use in hunting. They have only been seen used by the Super Predators to flush out their prey in the same way as a fox hunter would use hounds.

In the film, Predators (2010) a pack of Hell-hounds attacked Royce and his team, after the deaths of a few Hell-hounds, left 1 remaining about to attack Isabelle, she was prepared to kill herself with the pistol after her sniper rifle was jammed or reloading, the Hell-hound has stopped, which revealed that it responded to the whistle and retreats back to the Super Predators' camp, when Royce and his team followed it back to the camp, they found footprints of it, and led them to the Super Predators' camp, after the events through the camp, there were 2 remaining Hell-hounds with Tracker Predator after Tracker un-cloaked himself along with Falconer Predator and Berserker Predator, holding the 2 Hell-hounds on their ropes.

And they weren't seen again in the rest of the film.