Dolphins are small relatives of toothed whales. They are highly intelligent, very social creatures, who live in rivers and oceans throughout the world.
Dolphins attack in a manner similar ot their larger kin: tail-slaps, ramming attacks, and bites. They use their speed and intelligence both offensively (attacking in packs to take down large prey) and defensively (fleeing when an enemy proves difficult). Larger dolphins, such as orcas, may consider humanoids a potential food source. Some dolphins (such as narwhals or bottlenose dolphins) have special adaptations that enhance their charge attacks.
Dolphins are highly social, quite playful, and very curious. However, these traits take a decidedly dark turn when dealing with prey species (which sometimes includes humanoids): they play with their prey, attack in relentless packs, and wear away even at the largest animals in the ocean.
Dolphins seem to take kindly to most humanoids, most of the time, regarding them with a fond playfulness. They seem to have a problem with sharks, however -- the creatures rarely meet on good terms.
AKA: Killer Whale
Orcas are among the largest dolphins, and will prey on swimmers and people in small ships, if given the opportunity. They make use of their ram attacks to dislodge enemies from their boats or floats, splashing them into the water and making them easy pickings.