I own that same horse head mask. It’s in the drawer in my desk here at the office. Does that make my desk drawer dangerous as well, or was it just that particular horse head mask?
see CrazyIvan’s response.. there is room inside that horse head for a weapon such as a small explosive. A certain group of religious people are known to sacrifice their own lives with such weapons. Clearly he was white, but Americans have been known to convert.
rarestia is correct. A number of effective exploves could have been in the nose, snout, whatever you call it on a horse.