Dolphins aren't the happy, cute, cuddly clowns that most people believe them to be.
In fact, they kill for sport, not just jellyfish and porpoises but even their own kind! They hunt them down and ram them, effectively battering them to death.
They also practice kidnapping and they have sex for fun.
They're aggressive and they display sadistic behavior. They have been known to do good things yes, but they're not just wild animals, they're more like us humans than we'd like to admit.