Not much is known about the native life of the world, most noteworthy is the Yautja, but there also seems to be a plethora of wildlife.
Little is known about the planet. In Aliens vs. Predator: Requiem, it is shown orbiting a trinary star system and possesses a ring. Gravity, day/night cycles, atmospheric composition, continental distribution, etc., are unknown.
Terrain and Climate
The climate is presumably hot and humid throughout most of the world. According to AVP:R, intense volcanic activity is still present. The volcanic regions are also known to contain areas of lethal radioactivity, as the dangerous Vy'drach dwells in these areas.