Scientifically speaking, Monsters are defined as creatures with an inborn affinity for Ux. While some might not be much different from animals, that aspect allows for the separation. For some, this affinity arises as a unique kind of Ux: a Pseudo Type. So named because their Ux cannot create Krux.
As Monsters have a vast variety of appearances, abilities, and physiology, I’ll use a single Monster species to give an idea of what to expect; Floxes in particular.
Floxes are a very common, intelligent Monster that resemble bipedal dragons with fur instead of scales. A preference to fly rather than walk leads to the false assumption all Floxes waddle; ground-bound Floxes can walk and run as steadily as any other bipedal species. They can range from a mere foot in length, to close to six feet tall. Capable of human speech, and in fact have their own language, society, and culture, but a close proximity to humans over time added some human customs and familiarity. Personalities among them vary widely, but they tend to be very family-oriented, going as far as to forgo last names so marriages only bring groups together. A very social species, and have no misgivings with invading the personal space of someone they trust, and vice versa. As such, some elect to keep some as pets. There are debates on the derogatory nature of such an act, but the Floxes themselves don’t complain so long as they’re treated kindly.
The ability for a Flox to use Ux is at a baseline greater than a human’s, as every Flox, including Sereph Floxes, can use Air Ux with their wings to aid in flight, as well as “float” by expelling it from their wings. In addition to this innate Type, Floxes also have the potential to use other Types, two more being the most common. Floxes still can only have use of Air Ux, but such cases leave the Flox in particular with extreme flight capabilities. Floxes also have their own Pseudo Type, tied to their flight ability. While exceedingly weak on its own, Floxes with increased Air capabilities still have the potential to induce Changing in humans they encounter.
As you can tell, a Monster isn’t simply an animal with use of Ux. While most lack the capacity to speak human due to a very different vocal frequency, many still have their own language and intelligence at or greater than a human’s. Due to this intelligence, partnerships between humans and Monsters for Guild work and other activities are common. Humans who partake in such agreements are known as Beastmasters, even if a Monster is simply a pet to its owner.
As many early Beastmasters resent simple pet ownership classifying people as Beastmasters, they developed a ring system that allowed for greater connection between two Beastmasters, and a distinction from the common people. Any kind of jewelry can be used, but rings are the most common. A Beastmaster has a Monster condense its Ux Types in close contact with the ring and a clear coating on the ring quickly combines with the Ux to form a Krux. As these Krux are tied to the Monster via a means that hasn’t been fully explained, even far into Arkrux’s timeline, a Beastmaster can wordlessly communicate with their partner by manipulating the ring, commonly by twisting it on their finger to call them to their side if they wander.
Beastmasters also developed another tool to aid in their communication: a kind of electronic earring that translates the higher frequency languages of a Monster into something they can hear, which still requires learning the syntax and nuances of the language. In some cases, Monster species have a shared language, but only a scant few languages can be programmed in an earring at one time, leading to a tendency for multiple if the Beastmaster can afford them.
As a final topic, the husbandry of Monsters has been a common practice for humans and other Monsters alike, as they care for weaker or less intelligent species for mutual benefit as well as a sustainable food source. It’s rare for an intelligent Monster to be considered a part of this “Monster ranching”, rather as a partner to a Beastmaster due to moral and logistic issues. There are many who find conflict in any form of the practice, but they are a minority and the usefulness of the “livestock Monsters” is too great.
[Introduction]
A List of Monsters (Will be a masterpost.)
Floxes, Sereph Floxes, Monster Civilizations
Pseudo Types, Changing, [Ux Types]