Not all Dolphins are "Flipper"

One lone, sociable dolphin was locally
acclaimed for ‘saving’ a drowning boy (‘Flipper’); however,
others achieved notoriety for ‘abducting’ people who then had
to be saved by boat (e.g. ‘Donald’, ‘Percy’). At least 13 dolphins
had periods of mis-directed sexual behaviour towards humans,
buoys, and/or vessels, and approximately two-thirds (at least 18)
directed aggressive behaviour towards humans. Dolphin-tohuman
aggression sometimes resulted in such serious human
injury as unconsciousness, a ruptured spleen, and broken ribs,
(e.g. ‘Donald’, an unnamed dolphin from Florida Keys) or even
death (‘Tiao’).

Extract from: http://whitelab.biology.dal.ca/lb/Samuels%20Bejder%20et%20al%202003.pdf