Unicorn

Contrary to the popular Earth lore that paints unicorns as pure and wholesome, unicorns here are bloodthirsty and quite aggressive, bred as hunters. Their horns do have healing powers, which renders unicorn attacks quite painful as being impaled only prolongs the agony.
If confronted by one of these creatures, try to remember that they will not attack a person who does not run away. Which is not to say that standing your ground will necessarily end much better, but there are usually a few more tactics available in that instance.

Basic Information

Growth Rate & Stages

Unicorns are fully grown in size by the end of the first week of life. This does not extend to their intellect, however, and you can tell that a unicorn is young because it will stay very close to its mother for about two years before striking out on its own.

Dietary Needs and Habits

They are not flesh eaters. They eat plants. Mostly, they eat highly aggressive plants, which means that in an odd way they are good for pest control.
What they do is protect their food sources, and since those sources can be found quite commonly all over, this means that a unicorn deems the whole world to be its territory, and will thus defend it as such. Hence the aggression.

Additional Information

Domestication

Technically, unicorns are a domesticated species, as their natural hunting instincts were honed by unnatural means. So, by a rather twisted definition, since they are manipulated as a species to do the bidding of sapient species, they are domesticated. Personally, I would not take that as a sign that they are safe to be around.

Geographic Origin and Distribution

Unicorns can be found all over, but mainly in those nations that have made magic their priority. In the current age, the most unicorns can be found in Jovirenia.

Average Intelligence

Unicorns are fairly intelligent, but can get as single minded as a shark when on the trail of something. They are difficult to distract. However, when they are calm, they have been known to make their way into secure areas using magic.

Perception and Sensory Capabilities

Unicorns do possess magic, and it can be harnessed by outside sources. It is not concentrated in the horn, but since the horn is most frequently used against us, and also it's the most easily harvested body part, then this is what most unicorn-related recipes will call for.
The magic is inherent, and used heavily to help them hunt their prey.

Lifespan

Upwards of 500 years

Conservation Status

Unicorns are quite rare, but no one would be stupid enough to try and protect these vicious animals. They breed when they need to, and otherwise are quite long-lived and capable of defending themselves.

Average Height

Around 7 feet, but some have been known to be taller

Average Weight

Impossible to tell. The magic inherent in unicorns means that while they do have mass, it can't be measured properly. They might weigh as little as 5 pounds, but it's more likely that they weigh somewhere around 1500 pounds, the same as a horse of similar size