Many beverages derive from natural sources such as fruits, vegetables, grains. Other than milk, which beverages derive from the hides, organs, glands, bones of living creatures?

Various forms of soup/boullion are made from various animal parts.

For example, bone broth has increased in popularity in recent years because of the belief it is helpful in recovery from strenuous athletic activity and in protecting/rebuilding joint tissues.

http://espn.go.com/nba/story/_/id/12168515/bone-broth-soup-helping-los-angeles-lakers-kobe-bryant

Tribe in Africa, drinks blood. I know I'm spelling this wrong, but I believe it's the "Massai"

Many birds and msmmals regurgitate partially digested food to feed their young. I dont know how fluid it is but it is natural ;-)