If life on Earth was not strange enough, nature occasionally throws a very unusual creation into the genetic mix.
[The] 'wolphin' and 'Shetbra' are two examples of rare hybrids created when animals have mated across the species divide.
Kekaimalu the 'wolphin' was the result of the union of a bottlenose dolphin and a false killer whale, which is actually a member of the dolphin family.
The two parent animals mated while working together at Sea Life Park in Hawaii and Kekaimalu was born in 1985.
Her size - 600lbs and nearly 10ft long - colour, and shape are half way between that of her mother and father.
Perhaps even stranger is Nikita the 'Shetbra', the offspring of a Shetland pony called Linda and a zebra called Jonny in 2004.
They lived on a farm in Mongenzon, in north east South Africa, where Jonny learned to jump a fence between their enclosures.
The result was Nikita, who was born less than 50cm high, with very short legs, an unusually large head, delicate pointed hooves and stripes like her father.