In the horror-movie-remake-of-Free Willy-with-swans-instead-of-whales that is real life, a man in Des Plaines, Ill., a man who cared for swans, drowned after one of his own swans attacked and upended his kayak. The speculation is that Anthony Hensely came too close to a nesting ground and the swan went black swan on his kayak.
Swans are rumored to be highly aggressive animals (though zoologists suggest they are more bark than bite), particularly when it comes to defending their nest. This kind of death, though, is exceedingly rare. But seriously, swans look pretty scary. Do you remember what happened with Natalie Portman? And she was supposed to be the good swan!