Gray Short-Tailed Opossum
The thick fur is gray-brown on top with a lighter tone underneath. The hairless prehensile tail is used to grasp and balance while climbing. The muzzle is rat-like, with 50 very sharp teeth. The ears are large, very thin skinned, and sensitive to sound. The eyes bulge out giving them good night vision. The front legs are shorter than the hind legs.
STOs are one of the few marsupials without a pouch, meaning the young actually gestate outside of the body. The female has a circle of teats on her abdomen and when a neonate attaches to one of those teats it will swell inside the mouth, keeping the young firmly attached until it is ready to release. On the hind feet they have a big toe that is opposable and functions like a human thumb. They have pads on their feet and toes that enable them to climb smooth surfaces, such as glass. STOs are nocturnal and solitary.