The Viscous is an interesting creature on Daraction, they are slug-like, very large and are translucent. They are vicious at times, having very sharp teeth that are retractable, and can still be seen during retracted due to the viscous's translucent body. Viscous can also change their shape, in a way, basically they can just make themselves smaller so that they can fit into small areas such as caves, where many live.
This creature was named after the word "viscosity", which means how water can flow, something having low viscosity runs very slowly and holds its shape longer than high viscosity liquids, and since a viscous is slug-like and moves slowly and seemingly is composed of liquid, it is called the viscous.
There are no other types of viscous, just the standard.
Viscous have no certain location that they thrive in, most are in captivity, not because they are going extinct, but because they can be dangerous and enter the cities. Many wild viscous live in caves, and dark damp areas, because they easily can hide in areas and catch anything that enters. There are many viscous in the cave on Darkov.