Yautja Prime is the mysterious Predator homeworld which has been shown little in the movies and comic books. The information we do have is somewhat conflicting, mostly about the distance from Earth and the appearance of the surface. Here is a list of all notable references to the Yautja Prime, including the appearance in Aliens vs. Predator: Requiem and the Predator: Homeworld comic.
Yautja Prime in Aliens vs. Predator: Requiem
The most substantial appearance of Yautja Prime comes from the Aliens vs. Predator: Requiem movie, which is probably also the best part of it. We are shown a hot planet with flowing lava and no vegetation, although there seems to be at least partial cloud cover. Being a planet with a hot climate makes sense as the Predators love to hunt during the hottest periods on Earth. This climate might be the result of multiple suns, as the planet has at least two. The homeworld has multiple asteroids in it's orbit, which might hint at a destroyed moon or another cataclysmic event happening in the past.
The Surface of Yautja Prime
The planet seems to have a rough terrain with canyons and mountains. There are big stone structures in the background, including pyramids similar to the ones seen in the first Aliens vs. Predator movie on Earth. In the far background, we see tall buildings, possibly a Predator city with skyscrapers. A couple of Predator spaceships are visible on the surface, including Wolf's ship. Wolf himself seems to live in some kind of penthouse-like apartment with a nice display of trophies and quick access to his equipment and trophies. Wolf is able to travel from Yautja Prime to Earth in a matter of hours, probably due to his very fast ship.
The Game Preserve Planet in Predators
The Game Preserve Planet is the planet or moon on which the movie Predators take place. It is a jungle world with an atmosphere and vegetation similar to Earth. The Predators are known to bring humans and other prey to this planet for hunting. The planet seems to be close by or being orbited by other planets, one of which could very easily be Yautja Prime. 2 of the 3 planets shown in the movie are quite similar to what we see in Aliens vs. Predator: Requiem, including the cloud asteroids surrounding the planets. It makes sense for Predators to be allowed the luxury of hunting near their home planet, with humans being kidnapped from Earth for their pleasure. Some fans have speculated that the Game Preserve Planet is the actual Yautja Prime itself.
The Predator Planet in The Predator
The Predator planet shows up briefly in the recent The Predator movie by Shane Black. Through the bio-mask of the Upgrade Predator we are shown a hologram of a red planet and a Predator laying on a table with four other Yautja observing him. The Predator is being injected with an upgrade serum which triggers a rapid DNA reaction. The movie also hints that the Yautja are interested in invading Earth because of the planet becoming more attractive to them due to global warming. They want to harvest our best DNA and adapt themselves to Earth.
Yautja Prime in the Predator: Homeworld comic
The Predator: Homeworld comic offers us a quick glimpse at the Predator homeworld. Again, it seems to be a rock-based planet with little vegetation. The planet has two moons, a green one, and a red one. The Predators themselves live in simple tribal communities similar to Native Americans, in caves or simple structures. The characters in the comic speculate that the original homeworld of the Predators was actually Earth. They evolved on Earth swamps from reptiles and left the planet to seek a new home. That would explain why the Predators are somewhat similar to both humans and the reptiles of Earth and have a fixation on hunting on Earth.
The Population of Yautja Prime
The population of Yautja Prime is difficult to predict. They tend to live in smaller tribal communities and the existence of female Predators is somewhat rare, although in recent lore they have started to appear more frequently. Furthermore, Predators often get killed during their hunts and they are sometimes engaged in Yautja Civil War, which would dwindle their numbers further. Many groups of Yautja would have already left Yautja Prime behind as well, living on motherships or on other planets. A guess would be their homeworld numbers are more than a thousandfold smaller than humans, putting them in the hundreds of thousands, and definitely not in the billions or millions of individuals. Their population would consist of different types and ranks of Predators, including sucklings and younglings, young blood Predators, blooded Predators, elites, elders, and ancients.
Council of Ancients
The Aliens vs. Predator: Chained to Life and Death short comic also gave us a glimpse at life on Yautja Prime. It depicted towery buildings made of stone, reminiscent of Roman architecture both in the interiors and exteriors. Elder Predators were seen setting around a large table situated on a balcony, seemingly voting on some kind of issue after finishing a feast of exotic foods. The Aliens vs. Predator: Extinction game also described a Council of Ancients which was located on Yautja Prime. This served as a ruling council for the Yautja, with Predators with hundreds (if not thousands) of years of hunting experience making decisions for the Predator race. The council possibly served in conjunction with the Predator King, another ruler from the expanded Predator lore. Presumably, the King had a more of a presentational role and was called upon for meetings outside of Yautja Prime.
Yautja Prime Animals
The wildlife of Yautja Prime can only be assumed as there is not much evidence available. There are several animals that have a close connection to the Yautja, but it is unknown if they actually originate from the Predator Homeworld. The hell-hounds and dogs are such animals that help out Predators on their hunts. The dogs used by the Upgrade Predator from The Predator bare a closer resemblance to the Yautja themselves and are more likely to come from Yautja Prime. Another rare animal used by the Yautja is the war horse which they mount to move on their hunts quicker. The Predator horse was released as a statue by Sideshow collectibles. Although its head loosely resembles a Xenomorph, it is a unique creature not seen elsewhere in Yautja lore.
Hish-Qu-Ten Prime in Forever Midnight
Predator: Forever Midnight is a conflicting book released by DH Press in 2006. It ignored the Predators being called Yautja (like in the first Aliens vs. Predator novels) and called them Hish-Qu-Ten instead. The book explains a lot about the Predator culture and also some their homeworld. The Hish-Qu-Ten homeworld is said to be full of swamps, and the Predators evolved from swamp creatures. Some fans just choose to ignore this book, others consider the Hish-Qu-Ten to be another offshoot of the Yautja, just a different type of Predator. The Hish-Qu-Ten make another appearance in the Mortal Kombat X video game, as playable characters. The awesome cover of the book hints at the Predator homeworld in the background, although it is more similar to the Yautja Prime we see in Aliens vs. Predator: Requiem.
Yautja Prime in The Rage War Trilogy
Yautja Prime is mentioned at the end of the Rage War Trilogy. It is explained that Predator warriors are required to make a pilgrimage there at least once in their lifetime and that is a great honor for them. The planet is supposed to be very far from Earth and would take several months or even years to travel there using multiple dropholes (basically galactic space-gates). The book takes place in the distant year of 2692 and both human and Predator technology would be much more evolved by then. That is in conflict with what we see in Aliens vs. Predator: Requiem where Wolf is able to travel to Earth from Yautja Prime in mere hours in the year of 2004.