1. Bottlenose dolphin
Why pay lots of money to swim with these things if the also surprisingly dangerous? In truth the bottlenose dolphins is rarely harmful to humans but should it choose to attack then the very last place you want to be is in the water with it.
Along with the also unexpectedly aggressive short-finned pilot whale, bottlenose most awesome power that best not be underestimated creatures famed for their intelligence, they can and will outsmart almost anything in the ocean.