There are several cases of natural mutations in nature. Often, these mutations are minor and do not effect the welfare of the animal one way or another. But more extreme mutations could have a bigger impact. Either it could benefit the animal and allow it to thrive and pass on its useful mutation to offspring or the mutation hampers it and it has a shorter life with little chance of passing on its traits. The circumstances of the animal's interactions could tip the odds in one way or another.
An excellent example is a female boomslang found in South Africa. Not only was the snake leucistic, its scales which should be brown being white, but it was also born with two independent heads. The white and black pattern on its body didn't particularly work against it, the shadows of its arboreal habitat making it harder to tell where it is. However, two-headed snakes do not tend to live very long in the wild. Having two brains could cause indecision at a critical moment. Still, the boomslang's very noticeable appearance caught the attention of a wildlife preservationist who caught the snake and kept it in good care. News of this fascinating snake soon spread and it was eventually bought and sent over to Lyre for uplifting.
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"Are snakes the only two-headed animals we'll ever uplift?" asked one scientist casually to Judy.
"There are turtles who can have two heads," said Judy.
"I know it's not just a reptile thing," said the first scientist, "It can happen with mammals. There are cattle born with two heads."
"But they don't typically live very long," said Judy, "We're more likely to uplift a cow with polymelia."
The other scientist paused to think over the term. "You mean those cows with extra legs growing from their backs?" asked the scientist.
"Yes, they tend to live a lot longer, considering the extra legs don't interfere with their ability to eat and breathe," said Judy, "We'll probably be uplifting a six-legged frog as well."
"Those aren't easy to find, I bet," said the other scientist.
"Not entirely," said Judy, "They're more likely to happen in the USA because of some type of parasite here that attacks them when they're tadpoles."
"Almost makes me wish Project Chimera was about splicing different animal species together," said the scientist, "It would make this seem less like a freakshow."
"How would that be any less of a freakshow?" asked Judy.
The scientist tried to think it over before saying, "Let me get back to you on that."
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The two-headed boomslange arrived at Lyre without any trouble. However, administrating the Animalia virus was not quite so simple. The boomslang has a very potent venom. While not as deadly as the black mamba, even a small dose could be fatal if an antivenom weren't taken. Though the venom acted slowly enough for there to be time to take an antivenom and there was a bottle of antivenom shipped as well, there were few people wanting to work up the nerve of injecting the Animalia virus in fear of being bitten. Eventually, a syringe on a stick was used to provide the transforming dose.
The changes seemed to take a little slower to start, but eventually, the two-snaked started to grow in size. It easily lifted itself out of its tank and onto the floor. As it grew, the body structure began to change. A set of hips were filling out to determine where the waste was. The heads were given more distance from each other as a pair of wide shoulders formed. From those shoulders grew two appendages which became fully formed arms. The boomslang's heads started making moaning sounds as mammary tissue began to build up on their chest, swelling out into sizeable spheres before black nipples appeared on them.
The uplifted boomslang looked around with justifiable confusion. Unlike Iphis and Ianthe, they have not been given the hermaphrodite gene so their body was completely female. She had wider shoulders than most females, but that was more to accommodate having two heads. The head on the right, which was paler, asked, "Are we really two heads on one body?"
The head on the left, which had thicker stripes that made her look darker, said, "I guess that would make us sisters."
"But are we?" asked the right head, looking at her arm, "I didn't have this before."
"And I definitely didn't have this," said the left head, cupping her breast.
"You have become a part of Animalia," said Judy, "A community of uplifted animals like ourselves. My name is Judy, and your names, if you choose to accept them, are Medusa and Medea." The original pair of names was going to be 'Medusa and Minerva', but considering that Minerva was the one who turned Medusa into a gorgon in mythology, 'Medea' seemed less like forced irony.
"I think I would like Medusa," said the right head.
"I'll be Medea," said the left head, "Are other snakes like us?"
"If you mean your humanoid form, yes," said Judy, "But there's only one other uplifted snake with two heads. I'm sure you would like to meet them."
"I'd certainly like to," said Medusa.
"Me too," said Medea.