Save surfer from shark
On one hot August day, Todd Endris, 24 year old owner of Monterey Aquarium services decided to go surfing with some friends. While surfing, a 15 foot shark appeared. The shark tried to bite him but could not get its jaws around both the surfer and the surf board, it came around for a second try where it got Todd clamped between his surf board and its jaws, because his stomach was against the surf board Todd’s internal organs were not harmed, however he lost a lot of skin from his back, the shark let go and came at Todd for a third time and tried to swallow his right leg, however this gave the surfer the grip he needed to start kicking the shark in the snout until it let go, at this point when Todd was running out of energy and thought he was done for, a pod of dolphins came out and formed a protective ring around him, keeping the shark at bay long enough for Todd to catch a wave back to shore and receive emergency first aid from his friend.
Saves woman and child from being attacked
In 2008 a woman and her young son had been walking home from a playground; as they entered a parking lot a man holding a knife approached them and told them not to make any movements. A large pit bull ran out of nowhere and charged the man, who quickly fled. An animal control authority said they had no idea what the mans intentions were but it was very possible that the dog saved Angela’s and her sons life.
What’s extraordinary about this case is that every other item on this list the animal is either doing what they are trained to do or the person(s) was in clear danger from other animals. This is the only case I found in my research where the danger was another human.