Opossums have 50 teeth, more than any other North American land mammal.
Opossums have 13 nipples, arranged in a circle of 12 with one in the middle.
An early description of the opossum comes from explorer John Smith, who wrote in Map of Virginia, with a Description of the Countrey, the Commodities, People, Government and Religion in 1608 that “An Opassom hath an head like a Swine, and a taile like a Rat, and is of the bignes of a Cat. Under her belly she hath a bagge, wherein she lodgeth, carrieth, and sucketh her young.”–Wikipedia
