<Types and Colors>
(cont.) These dragons are omnivorus, however different mimics tend to eat different things. The smaller ones, like coin and sword mimics, tend to eat more fruit and veg with the occasional mouse or lizard that strays too close. Larger ones, like chest mimics, have a wide veriety. Most are primarily meat-eaters, sometimes even eating humans and their crops in one go, while others tend to be more peaceful and are primarily plant eaters.
Mimics can hibernate in one position for even years at a time. However, once something disturbs them, they're awake.
There are many different types of mimics, but I'm only "showcasing" three - the sword, the coin, and the chest.
Coin and sword mimics are the smallest, both being able to fit into the palm of your hand. Coin mimics live in claw-crafted discs, tall and wide enough for them to fit in. They mostly come in gold colours, but can come in silver and bronze variants too.
(cont.)

<Types and Colours>
Sword mimics come in a range of colours, usually taking on the colour of the hilt and handle of the weapon. They sit upon the hilt as if they are some sort of special ornament. These mimics are very protective of their item and tend to attack immediately after being picked up.
Chest mimics either take on the colour of the bottom of the chest they reside in (to blend to it), markings that resemble coins and gems all over their hide, or a golden colour to look like a sea of coins inside the chest. Sometimes, there can be actual coins in the chest to throw adventurers off, and sometimes they can be coin mimics. Usually, the smaller dragons hunt for food for the larger dragon in turn for protection.
There are other types of mimic dragons, however they will be covered later.

<Areas of living>
Mimic dragons are everywhere, but most still hide in caves, mountains, and old castles, where adventurers and explorers are sure to explore and, in some cases, meet their doom. These places are usually overrun with plants and wildlife, which these dragons feed off of. However, some choose to live in abandoned houses.

<Characteristics>
Mimic dragons can be identified only by sound, as when they're not away from human eyes, they're completely still. The only way to find them is to listen for the faint sound of breathing. If you can hear it, then it's a good sign that you should leave the area if you want to return home unharmed. Mimic dragons tend to attack on the sight of a human, due to some kind of evolutionary memory that fuels their hatred and reminds them constantly that humans once brought their race near extinction, and that they should pay for that. Some, however, have been able to look past that in recent years, and have been able to interact with humans peacefully.
The most aggressive type of the species is probably either sword or rock mimics, while the most peaceful would be the box (not chest) or "monster under the bed" mimics.

<Appearance>
All mimic dragons look the same, despite their size and colour differences.
They all have a mane of "fur" running from the forehead down the spine, either ending at the base of the neck/shoulders or at the base of the tail. Their wings all have three "fingers" in them if you think of them like bat or wyvern wings, except without the claws on the top of the wings.
The horns are always as shown above - up, towards the nose, then up into a point. However, they can be varying sizes.
The ears they have are quite mammalian, but they're covered in scales instead of fur.
The front paws consist of three "fingers" and a "thumb", while the back paws only have three toes.
The tail blade is usually diamond- or triangle-like in shape.
The eye colour of mimic dragons varies as much as the dragons themselves, though they don't connect to what type of mimic they are.

<Family and relationships>
In order for a mimic dragon to become a specific mimic, they do not have to be born to the same parents. For example, the child of two coin mimics could become a chest mimic if they find an unnoccupied one to live in. Genetics have nothing to do with the type or colour of scales, but do correlate to eye colour and body types.
Mimics tend to lay clutches of 1 to 4 eggs.
Mimics also tend to make relationships with others of the same species easily, much like chest and "treasure" mimics (coin, sword, ect). Sometimes, solitary mimics like rocks or chests (without treasure mimics) can "adopt" an animal native to it's territory to keep as a companion, giving protection for recieving friends basically.
As mentioned before, mimics tend to have a negitive attitude towards humans. However, this can be changed by seeing that some humans can be kind and caring, instead of being the rutheless killers they "remember" that they are.

<Other/forgotten info>
Mimic dragons tend to live, on average, for seventy years. The longest living mimic was around one hundred.
Smaller mimics can be seen as prey for larger predators, so they need to either live in large groups or with a larger mimic.
Rock mimics are the only subspecies of mimics to vary in size, as some can be as big as boulders while others can be as small as pebbles.

Great species! I really like how much thought you put into them, everything's very detailed and complex. I haven't had time to read the entire description yet, but I skimmed through it and what I did read sounds pretty cool. X)
Are you gonna make OCs of this species?