An otherworldly, spirit slime.

They are beings of possession, their bodies made of a slimelike material. The mask can be really just about anything. Maybe more wolf shaped, more humaonoid, or so on. The mask is the pivotal part of their form as it houses their conscience. If the mask breaks the creature dies.

There are many ways the mask can form. It can barb straight through the body, it can spider from behind. But more often than not it's usually holding the mask to the head in some way so that you can't just pop it off. The moment you start flashing a light on it, or shine a torch on it, it could wound up attempting to devour.

Putting on a pacified (it's their "mask only" look) Ethomire will result in instant consumption and assimilation.

The creatures can be vast colors. Red, blue, green, yellow. Typically matching enviornments more often than not. Green are the most common, blues are less, reds being uncommon, and yellows being exceedingly rare.

Greens are most common because they're found near lush greenery. And considering their enviornments revolve around moist areas, swamps and overgrown caverns are natural. Blues live near lakes and bodies of water, reds live near magma (because of the heat it's rwby they're so uncommon) and yellows have no habitat they're basically just albino green.

If a mask were to chip at the face, but it were to gain a form again, it would lose some capabilities. It could miss an arm, or a leg, or some sort of chunk of its body. The only way to get it back is for the mask to heal itself. While the body can heal in seconds, the mask can take up to a month to heal a single chip.

If it cracks down the middle and miraculously survives, it could take years to return to normal. Although, the healing process can be accelerated drastically when a host puts on the mask. Problem is, Ethomire cannot force its mask on others. If one were to put it on another, or one were to willingly put it on, it'd be able to consume the host and heal most of its cracks and chips if not all.

Basically, it can't do it itself. But others can do it for them. This includes other Ethomire putting them on other creatures.