There are quite a few furs wear fursuits and are often criticized by mundanes with "dressing up is childish". "Playing pretend is childish". Both of these statements are false. Allow me to explain.

There are plenty of examples of humans wearing animal-like clothing and most of them are adults. The Egyptians had a mummification process in which jars with animal heads were used to store organs. These creatures were a baboon, a falcon, and a jackal (there was a jar with a human head as well). These animals were supposedly the children of Horus, a hawk headed man who was god of the sky. 

Native Americans often performed a Buffalo dance that was thought to bring good hunting in the prairie. This dance consisted of one or more people wearing buffalo skin and acting as a buffalo while holding a rattle and stick. Another person (or people) would imitate chasing the buffalo in the dance. This reenactment was common between Mandan, Sloux, Cheyenne, Pawnee, and Omaha tribes.

Playing pretend isn't as childish as it seems. Actors pretend to be different people to fit the part they were chosen for. Hamilton lead actors on Broadway are paid $116,300 annually to pretend. Most actors only rely on acting to bring home the bacon.

(Read more about Hamilton and their pay checks here at: http://time.com/money/4362742/hamilton-cast-earnings-lin-manuel-miranda/)