For the #Age-of-Avians
The Oposstalker is the descendent of the opossum and is one of the few mammalian top predators in the Age of Avians. Oposstalkers inhabit lower North America and an island that is a small broken-off piece of Florida. An oposstalker can grow to be 4 feet in length from head to tail. Oposstalkers have evolved a pair of thumbs on their front paws and two dagger-like fangs designed for stabbing into the throats of it prey, which happens to be; anything it can catch.
Oposstalkers in most of North America have faced competition with many North American predators and therefore had to devolve into cowardly scavengers that are somewhat smaller in stature and lack fangs, however, those who inhabited the tip of Florida avoided competition when the tip of Florida broke off and therefore retain there size, fangs, and status as an apex predator.
P.S. This was suppose to look more opossum-like but I think I failed at that.