There are four rarities to Fluogens. The two main ones are common and rare, those will be represented here. The other two are mutation, for which traits can be found in the Shop section, and Crossbreed, which has a set of rules at the bottom of the page.
There are a few basics to every Fluogen! The basic elements that make them individual are their ears, horns, tails, feet and unique patterns and coloring. Starting with the feet, they all have digigrade legs, but the feet have three categories. It's common to have paws or hooves. On rare occasions their hooves can be uncovered to show their glass.
Typically Fluogen ears will come to a single point, though they can be any size or point in any direction. Any ears that have additional points or shapes would be considered rare. Additionally, any sort of mammal ears are a mutation.
 Their horns can come in any shape or size. The most common is to have two horns. However, on rare occasions their horns can connect or they can have a different number of horns.
A Fluogen tail is composed of a cone like shape covered in fur. Any amount, length, pattern, or texture of fur is seen on a common tail. Rare tails are: any number higher than one, tails split into two or more in the middle, tails that show their glass, and tails that are shapes other than the cone. Tails that mimic non-mammal tails are crossbreed only traits.
Scars in the skin will show the glass underneath. In rare cases, the skin will never grow, showing the glass underneath, which leaves the glass more open to cracks and breaks. Though when breaks occur it is possible to replace them with any kind of prosthetic imaginable.
The trait that all Fluogens who developed their skin will have is the diamond shaped window on their chest. This window shows the essence that flows beneath their glass. Most commonly the essence will be one color, and the glass will be the same color but lighter. In rare cases the essence can have two tones, more than that is considered a mutation. Other rare cases are: the glass can be colored either a different color to the essence (in a gradient or solid), the glass will be darker than the essence, or the window will be in a place that isn't the chest.
Other important things to note about a Fluogen:
They do not have pupils.
Unless they have a claw mutation, they do not have nails.
They do not have bellybuttons.
Most importantly, have fun with any patterns or markings on their skin / fur. There is no rarity to the patterns or colors, so go wild!
Have a crossbreed MYO? How lucky!
For the most part, the sky is the limit! Though there are a few things to remember to always have with your fluogen.
They should always have a window. Though crossbreeding can change the shape, a window should always be present.
Their eyes / mouths will always be the color of their essence.
Unless they have an animal ear trait that replaces the horns, they should always have horns.
Crossbreeding can only effect the physical bodies of the Fluogen. The Essence remains unaffected by the crossbreeding process.
Likewise, they will always have the glass body underneath the "skin". So crossbreeds that change the skin makeup, such as candy or plushie, will only have that make-up to the interior glass.
Things that you can do with a crossbreed:
change the feet to other animal's feet, add parts of other animals, centaurs, snake tails instead of legs, make the skin other materials, extra eyes, and so much more!