Mutation is absolutely necessary for the evolution of the species; however, some significant mutations can be detrimental to an individual’s survival. Here, we share some of the most shocking mutations observed in animals:

Two-headed cow

This unique calf was born on a family farm in Florida in 2015. Named “Annabel,” she has two heads, four eyes, two mouths, two noses and two ears.

She was too weak to lift her head and nurse, so her devoted family visited her regularly with bottles of milk. Unfortunately, there was nothing the vet could do to help her; The longest recorded time a two-headed calf has survived is 40 days.

Mountain lions have a second jaw

Deformed mountain lion. Idaho Fish and Game’s photo.

According to Idaho Fish and Game, this particular animal was legally harvested in Preston, Idaho after someone observed it attacking a dog.

The hunter was extremely confused when he approached the animal – it had a full set of teeth and small whiskers growing from its forehead. Apparently, this is evidence of the remains of a conjoined twin that died in the womb or a rare tumor.

Two-headed shark

Shark fetuses with two heads are becoming more and more common around the world. The mutation that leads to the development of two heads is called axial dichotomy and it has been seen in other animals – even humans. In these sharks, if they survive birth, it is unlikely they will live long in the wild.

Scientists are still trying to figure out why this happens. The most common theory is overfishing, which would lead to a smaller gene pool and a greater susceptibility to genetic mutations such as axial branching. Other possible causes include metabolic disorders, pollution, and viral infections.

Goats have 4 extra limbs

This 8-legged boy was born on a farm in northeastern Croatia. Not only does it have twice the normal number of legs, but it also has both male and female reproductive organs.

The reason for this is that, like the mountain lion, the goat possesses the remains of an underdeveloped twin. Dubbed “Billy the Squid,” he may not survive more than a week.

Three-headed frog

“Froggy”, a three-headed, six-legged frog was discovered in the waters of a seaside resort in Somerset, England after escaping from captivity.

This amphibian’s unusual shape could be the cause of a random genetic defect or water pollution. “I have never heard of a frog like this before,” said biology professor Tim Halliday. People have been reporting mutant frogs for the past 200 years, but finding one with three heads and six legs is very rare.”

Ducks have 4 legs

The four-legged duck “Donald” was hatched by a family in Louisiana in 2014. Apparently healthy except for his two extra legs, the bird survived into adulthood and even has his own Facebook page.

Donald was treated by veterinarians at Louisiana State University, who attempted to bandage and splint one of his good legs to help him walk. His owner reported on Facebook, “The therapy we’re trying and the brace on his left leg isn’t working well.. but we’re still trying.” Really Luckily, he passed away 2 months later.

Two-headed snake

Meet the albino two-headed Honduran milk snake named “Medusa” – worth about 50,000 USD. The owner of “Venice Beach Freakshow” paid a huge amount of money for this beauty.

“I wanted her since the day she was born,” he told Huffington Post. He continued: “The snake is perfect. Some other two-headed snakes are very beautiful, but they have a twist that makes the two heads become one. Medusa does not. It was as if she was born to have two heads.”