I did something similar once. I was in the gorilla house at the National zoo and there was a lone silverback in the indoor enclosure. So being the idiot I am, I thought it would be fun to taunt him by banging my chest and scratching under my armpits. He very much did not like that and bound across the enclosure with one leap (about 25-30 feet) and punched the glass that my face was pressed up against, then proceeded to throw everything in the enclosure. I stood at the glass in shock at the speed he made up the distance between us, and my wife (girlfriend at the time) just looked at me with a sense of profound disgust.

The lesson I learned that day is never fuck with a silverback.

As an added bonus as we walked out of the gorilla house the orangutan was going by on his ropes (which cross over the path the people walk down), and started peeing on everyone below. Fortunately we were outside the path of the stream, but it was damn funny, and he looked to be thoroughly amused.