Dynastinae, Rhinoceros Beetle

This one was in a wildlife centre, not in the wild unfortunately, but they are found in Costa Rica (as well as other places in the world).  Wikipedia tells me they are the largest of the beetles, reaching more than 150mm (6 inches) in length.  They are completely harmless to humans, and eat dead wood, grasses, leaves, fungus and fruits.  This one is loving it's watermelon.