The head and body length is 180-290 mm, tail length is 270-490 mm and weight is 0-500 grams. They usually have an ornate color pattern, including the diagnostic stripe which extends between the ears and eyes almost to the nose. The prehensile tail is longer than the head and body and the terminal portion is hairless, with color variations from cream to pink.

They are more arboreal than other large opossums, generally inhabiting forested country and living in tree hollows or limbs. They are most active during the evening, night or early morning.

Their natural diet consists of fruits, seeds, leaves, soft vegetables, insects, and small vertebrates. They may also feed on carrion.

Caluromys lanatus is found in N and C Columbia, NW and S Venezuela, E Ecuador, E Peru, E Bolivia, E and S Paraguay, N Argentina (Provincia Misiones), and W and S Brazil.