The snowstalker (Gulo fatalis) is a large, solitary, saber-toothed, white-colored musteline mustelid from the North European Ice of 5 million AD. It has evolved from the wolverine (Gulo gulo), and is the chief enemy of shagrats.
One big difference that the snowstalker has from most other mustelids is its method of killing prey. Its canine teeth have developed into 6-inch (15-centimeter) slashing weapons, designed for inflicting deep wounds on large prey bigger than themselves (a case of convergent evolution with saber-toothed felids). It weighs about 75 pounds (34 kilograms) and measures 19 inches (48 centimeters) high at the shoulders, larger on average than any Human-era mustelid. It is territorial, but as the tundra on which it lives supports very few large plant-eaters other than shagrats, there is little in the way of regular prey here. The territory of a single snowstalker covers several square miles.
Because of the large distances between the territories of neighbors and potential partners, snowstalkers mate infrequen
tly. Thin populations such as this are prone to inbreeding and the genetic weakness it brings, so the snowstalker has evolved a way to overcome the risk. A female snowstalker enters estrus, her fertile period, every 21 days. Each time she mates, the fertilized embryo is held in a kind of suspension. The embryos are eventually implanted in the womb and the litter is born as the winter ends and the summer thaw begins. This means that the young come from many different paternal lines. Delaying implantation in this way aids the spread of diverse genes.
Large prey is hard to find on the tundra, so when a snowstalker spots a herd of shagrats it will follow it for days. Finding food is particularly important during the summer thaw since, like the shagrats, a female snowstalker has young to feed. Each day takes her further away from the lair where her litter is waiting, bringing her deeper into the territories of other snowstalkers. As there are things like shagrats on the fields, the snowstalkers have a good supply of meat. Sometimes, hunting female snowstalkers will conserve their energy by letting a larger male (who she is hunting in the territory of) do some killing for her.
Their dens where they both alone and with their cubs are in shallow caves - the only shelter they can find in the bleak landscape. Even at such young ages, snowstalker cubs are ferocious and competitive. Mothers can travel to find food for their young as far as the western coast.
Snowstalkers and other predators that travel towards coastal areas in the west will come across such coastal creatures as gannetwhales. They will attempt to eat the large eggs of the gannetwhales, but can repelled away by both wounds given to them by the long beaks of parent gannetwhales and from being forced away by the noxious regurgitation the large birds will make, too much for a snowstalker's sensitive nose.
During winters, especially when there are blizzards, snowstalkers will use their white coloration to blend into their surrounding to ambush prey like shagrats. Shagrats get wounded form these attacks, but a snowstalker does not risk injury by trying to finish it off. There is no hurry, for it simply trails its victim and waits until the shagrat bleeds to death. During the summer though, while boggy greenery is flourishing, it is at a disadvantage, though they can attempt to ambush on rocky terrain that still has some snow on it. They will attack weak or inexperience individual shagrats (and other prey), dispatch the prey with their saber teeth and monopolize the carcass, defending it against any other rival of the same gender that approaches. A male shall defend the prize against any rival males, but a wandering female, on the other hand, will be allowed to eat her fill in return for mating rights. Afterwards, a newly-inseminated female will return to her lair and regurgitate most of what she has eaten for her cubs.
Snowstalkers also have hairy soles to their feet to insulate them from the cold and give them some grip on the slippery ice.