Humans are not the only beings with mana. Edible and domestic animals possess inactive mana, which in human terms can be considered to possess Red aptitude.
However, when an animal possesses active mana they are called beasts. They bear great resentment to mankind and are highly hostile to them.
Beasts can perform some specific types of magic and possess unique abilities per species or family (not per individual as in the case of humans).
Beasts are classified according to several factors, among them the difficulty of eradicating them, the power of their mana and the type of abilities they possess.