Rajang Ecology

Disclaimer: This is merely a plausible explanation for the monster(s) in this article, and should not be considered canon.

In-Game Information
"Ultra-Aggressive creature that is rarely sighted and seldom survived. Survivors report it exhibits a strange attack.  The Rajang is said to be a loner, and this isolated life has made it difficult to pin down its territorial leanings."

Taxonomy
Easily the largest and strongest of known Primatius; Rajang resembles a Blangonga but with a much darker coloration and two long horns. Unlike other Primatius species, Rajang is the only one to exhibit the ability to generate large amounts of electricity. The only known creature with a stronger electrical output is the Legendary White Fatalis. But this is besides the point.

Habitat Range
Due to the Rajang's near-permanent nomadic lifestyle, it's not entirely certain where all the Rajang CAN live (though it's not farfetched to assume that it can live just about anywhere). However, there have been regular sightings in high-altitude areas, for the most part, so it's safe to say that "If there's cliffs, there's Rajangs". This common phrase is a direct result of its two most common habitats: Mountainous regions (volcanic or frozen; the Rajang apparently doesn't care) and canyon regions.

Ecological Niche
In almost any habitat that the Rajang happens to be passing through, it enforces itself as the apex predator of the surrounding area. Its nature and adaptations allow it to hunt and prey on virtually anything smaller than itself, and anything larger (such as a Tigrex, which also inhabits similar environments) tends to avoid it due to its absurdly aggressive behavior.

On an interesting note, The Rajang is believed to be the sole predator of the elusive Kirin.

Biological Adaptations
Rajang is one of only a handful of monsters able to wield deadly lightning. How it produces it's charge is unknown, but most likely tied to static electricity created by the beast's fur, or an electrical inner organ. Rajang are extremely fast and nimble despite their size. Rajang appear to have very poor eyesight, relying mostly on smell to accurately find prey. Rajang exhibits extreme physical strength, easily knocking a hunter off his feet and into the air. Rajang's natural high aggression and rage only seem to amplify it's strength and electrical power, forcing it into a "Golden Rajang" (nicknamed "Super Saiyan") state. When golden, Rajang is even faster and more deadly than it's already powerful base form.

Behavior
Outwardly, the Rajang is considered to be the most aggressive species of Primatius known thus far, and as such, many consider this to be an outright brutal creature in all its aspects. This however, is surprisingly untrue.

It's a common belief that the Rajang is a loner due to being highly territorial, and this thinking leads people to believe that Rajangs will typically attack each other on sight. In a sense, that's correct. Rajang are unique in that they're the only known species in its genera to live a majorly solitary lifestyle (as opposed to the far more sociable Congas and Blangos), and can go months, even years on occasion, without ever making contact with another of its kind. However, in the chance that two meet, something completely fascinating occurs.

Upon making eye contact with eachother, the two Rajang immediately enter a state of apparent rage, golden hairs standing on end. The two lunge at each other, lock hands, and proceed to roar at eachother and emit small bursts of energy at the other's face. After a minute or two of this, they headbutt and jump back simultaneously. After this dangerous encounter, something unexpected happens. The two Rajang calmly walk up to eachother and, in an unforseen act of passiveness, begin to nuzzle eachother and groom one another with their horns. Regardless of the two companions' genders, the beasts will stay together for around a week, doing practically everything together. This is an easy thing to spot, as the population of many herbivores in the immediate area will plummet during this timespan.

Assuming the two are of opposite genders, they will also mate during this time period, and after a gestation period of roughly 6 months, the female will give birth to one or rarely two offspring. An interesting thing to note is that the offspring will have a fur color that is predominately the same color of the surrounding environment. It is unknown how this is determined genetically, but regardless, the effectiveness of it is apparent. During the two-year time period that the young stay with the mother, the mother stays in a near-constant state of rage (or at least, it appears as such). This is also accompanied by a surge of adrenaline, resulting in strength and tenacity far beyond the creature's already unsurpassed abilities.

As one should already be well-aware of, the Rajang is infamous for its aggressiveness (aside from the points above). This is attributed to what some believe to be the beast's poor eyesight (which is understandable: they even attack each other initially, perhaps as a result of not recognizing each other). Against most prey, the Rajang will quickly and effectively pummel the target to death using either its fists or its horn. In the chance that the target food is too far away - or too fast - the rajang will expel either a burst or beam of energy, usually paralyzing or killing the prey, usually instantly. Either way, the result is an easy meal for the Rajang.