In 2007, a tiny chihuahua fought off a rattlesnake to save the life of a one-year-old boy in the USA. The child, Booker West, was bathing outdoors near his grandparents' house in Colorado when a rattlesnake slithered up behind him. The dog - Zoey - on seeing the advancing rattlesnake, jumped into the picture and was bitten as she attempted to rescue the child.
Monty Long, the boy's grandfather, said: "She got in between the snake and Booker, and that's when I heard her yipe."
The story ends well for the little dog. Given very little chance of surviving the snake's bite, Zoey soon made a rapid recovery and the last we heard, had returned to her usual self.
Dolphins Rescue Surfer from Great White Shark
Dolphins, shark deterrent
Dolphins, regarded as one of the most intelligent and compassionate animals in the world, have a long and friendly history with mankind. Stories of dolphins protecting humans date back to Ancient Greece.
And it isn't just human beings they save. In 1983, a pod of dolphins worked with humans to save a herd of 80 stranded pilot whales; the dolphins, who somehow figured out the danger to their sea-faring friends, put themselves at personal risk to save the whales. An impressive 76 of the 80 whales made it back to the ocean alive.
There were more dolphin heroics in 2007, when Todd Endris, a surfer off the coast of California's Marine State Park, was attacked by a great white shark. The shark peeled skin off and chomped his legs to the bone when a pod of bottlenose dolphins came to the fore, formed a protective ring around him and helped him return to shore.
The shark that attacked Endris was believed to be 12ft-15ft long.
Lulu the Pig Saves Heart Attack Victim
Pig, heart healer
In 2002, JoAnn Altsman had a heart attack while on vacation in remote North Woods, Pennsylvania, with no other human being to call upon. Lulu, her pot-bellied pig, escaped from Altsman's locked cabin, ran to the highway and blocked traffic - by sitting in the middle of the road - until she was able to bring help to her friend.
Whale Saves Diver Suffering from Cramps
Whale, deliverer of divers
In July 2009, Yang Yun thought she was on the verge of death when her legs suffered debilitating cramps in freezing temperatures while taking part in a diving contest in China.
Yun felt her legs crippled by cramps when she was trying to return to the surface.
"I began to choke and sank even lower and I thought that was it for me - I was dead. Until I felt this incredible force under me driving me to the surface," she explained.
The "incredible force" was Mila, a Beluga Whale, who used her nose to push Yun to the surface, thereby saving her life.
Jambo the Gorilla Protects Five-Year-Old Boy
We round off our list by going back to 1986. Jambo, one of the world's most famous silverback gorillas, was the global poster boy for his species and was born in Switzerland's Basle Zoo. The term silverback is used to describe adult male gorillas, which can grow up to 5ft 11in in height and weigh up to 600lb. A menacing sight.
Gorillas, however, are among the gentlest of all animals and Jambo demonstrated that when a five-year-old boy - Levan Merritt - fell into the gorilla enclosure at Jersey Zoo. Although definitely not carnivorous, even an inquisitive gorilla is a danger to so young a boy and movement from other members of the herd suggested Merritt may be attacked.
Jambo was quick to act, though, and placed himself between the boy and the rest of the herd. It was a clear sign from the group leader - leave the boy alone.