The common and brown unicorn species reach no higher than knee height on an average faleigh; black unicorns are a few centimetres bigger. Grubbing unicorns, the largest species, are knee height to a rocca. Little unicorns - the smallest species, quite rare and declining in number - are cat size.
They are covered in short fur, sandy (common unicorn), brown (little, brown and grubbing unicorns) or dark brown (black unicorn) in colour. They have rubbery hoof-like toes. Both sexes feature a single, gently curved spiral horn in the middle of their foreheads.
The horn is used to wound attackers and, in males, in contests for mating rights. Unicorns' teeth are similar to rodents'. The grubbing unicorn also has small tusks like those of a wild boar.
Unicorns form herds with a social structure like deer. Roaming bachelor herds tend to be the most aggressive.
Unicorns are found in the greatest numbers in unhealthy countryside or woodland. They are commonly viewed as pests. They do not venture into inhabited faleigh settlements but will come right up to the boundaries and scavenge around rubbish tips and cesspits.
Unicorn horns were commonly believed to be poisonous, though in fact they are merely full of bacteria because the creatures cannot properly clean them.
In popular legend, dragons can cure unicorn poison. ('Dragons' of the sort meant by this legend are purely mythical on Shade. Terrimoirine folk have never heard of ijsdrakons, which are not found in unicorn territory anyway.)