Marsupials are incredibly interesting. They are found in Australiasia and only one type of mammal in North America shares these marsupial characteristics - the Opposum.
Marsupials are unique in their reproductive capacities as an under developed fetus is born from an internal yoke filled sack only to climb up into a hidden pouch housing nourishment for continued development. This is incredible. Marsupials are not placental mammals and yet most development takes place in a sub-internal pouch. The rite of passage the fetus makes immediately after birth is unbelievable. It is the size of a small worm and yet it makes it's way up to the pouch instinctually and with great effort.
Did you know there is even a marsupial mole? Fascinating!
Source: https://www.pinterest.com/pin/138907969736122401/
David Attenborough elegantly presents the birth of a marsupial (kangaroo) - the marvels of nature!
References
http://www.ucmp.berkeley.edu/mammal/marsupial/marsupial.html