Dolphins are assholes. To quote
Cracked.com because I cant be assed to write it out myself:
After the messiah-like lions, the animal with the best reputation in the entire World is the dolphin, a sort of combination of Buddha and Aquaman. When dolphins are not rescuing swimmers from sharks, they are using their magical dolphin healing powers to make paraplegics walk.
Why Are They Assholes?
Besides also being among the smartest things on Earth, dolphins share another characteristic with humans: they're the only other animal that will kill for fun.
Back in the late nineties, marine biologists began to find lots of porpoise carcasses that had seemingly been punched in the gut until they died. After rounding up the suspects, putting them in the line up, the porpoise widow pointed at the guilty party: asshole bottle-nose dolphins.
Porpoises don't attack dolphins. They don't even eat the same food, so they can't be fighting because they hog all the good fish. And the fight is not for territory, since porpoises are't just chased away but actually stalked and then killed.
There are only two explanations left: either "Because dolphins think killing is freaking hilarious" or because "Dolphins kill porpoises as training for when they have to kill baby dolphins."
It turns out porpoises aren't the only animals turning up floating in the sea after meeting dolphins; the other ones being baby dolphins themselves. Some marine biologists believe adult dolphins kill babies for the same reasons lions do, to bang dolphin moms, except that there are reports of female dolphins also killing dolphin babies, which either destroys the theory or makes it much, much sexier.
To make matters sound even worse, scientist say dolphins use their sonar to pinpoint their victims' vital organs so that they can cause the most damage when they hit them.
Now, there aren't many cases of dolphins attacking humans, so at least there's that. But dolphins violently humping humans? Hell yeah!
The source has some pictures and videos of dolphins raping people.