I just came upon some great footage on You Tube, from David Neils. It shows three elk playing in a forest puddle. Embedding is disabled on that particular clip — but you can link to it here: Three Elk Calves in a Puddle.
This companion video below, also from Neils, shows what most people would construe as play — among elk calves. Of course, since we don’t know what’s in their heads and hearts, there will always be people who call “anthropomorphism” when you suggest that animals share some of our qualities and capabilities, including playfulness. Well, anthropomorphism is a sticky point in my personal philosophy so I’ll gladly take the hits when I say, yep, wild animals have fun, too.
You can learn more about David Neils and his trail cam work at his website Off the Pavement.