The is the black eared possum (Didelphis aurita), also known as the Gambá-de-orelha-preta or Saruê, a species of opossum found in Brazil, Argentina and Paraguay. A bit bigger than other possums in South America (60 to 90 inches long and up to 1.6 kg), but with a relatively shorter tail as it's not in the trees quite so much. They do climb of courrse, just not so fast or dexterously. On the other hand, on the ground they are faster than other possums and it's been shown they can see quite a lot further.
So what do possums eat? Well, pretty much everything. Insects, fruit and lots of small mammals, they have actually been recommended for keeping down levels of mice. Rather more impressively, they also go for snakes! Somehow they manage partial or even complete immunity to the venom of many species including the fer-de-lance, Bothrops asper, whose bite can be fatal to humans.
When they meet something too big to eat, and too fast to run from, they "play possum", ie. play dead. This can be surprisingly convincing, even including a smelly secretion to suggest that they've started to "go off". As many predators prefer live food this is worth a try as a last resort, but it doesn't work terribly well against oncoming traffic. Nonetheless the Saruê is a success story, and has otherwise adapted well to the modern Mata Atlantica.