Aside from their reputation for ferociousness, slar are characterized by their bright bluish-green appearance. In fact, several harmless herbivores on Port Evokk have a very similar shade of color; xenobiologists believed these animals evolved this adaptation because predators recognized the brilliant coloration and mistook the animals for slars.

Slars have large and powerful legs which they use to leap great distances. Their hooves are designed to dig well into the ground for additional distance. They have long, well-muscled tails, and coil them around tree limbs or other solid objects, allowing them secure positioning while finishing off a kill. They have three elongated claws on each "hand," as well as flexible membranes between each finger, allowing them a wide span. They use these claws to pin potential targets to the ground (or other suitable hard object). Their most lethal weapon, however, is the crown of razored quills atop their heads, which quickly reduce a meal to shreds.

Slars are doubly dangerous because of their behavior. While they need to feed only about once every three standard days, their feeding patterns are irregular. Sometimes a slar will go eight or nine days without feeding, even with ample food sources nearby. Other times, a slar will feed three or four times in a single day (sometimes within two or three hours). Slars have been known to lay, seemingly at rest, for hours at a time while animals frolicked mere meters from them, and then suddenly attack without warning. Their feeding frenzies are not for the faint of heart.

Slars are avidly hunted on Port Evokk. While it is readily acknowledged that they are a public health threat, slars have industrial uses. Their quills are often used in cheap industrial razors, while its digestive juices are used to waterproof ansmul-hide boots and jackets, which are popular in local communities.