Ilya Ivanovich was a Russian biologist born in 1870 who in adulthood obtained an impressive set of achievements in his field, which happened to be artificial insemination. It was said that he could inseminate 500 mares with the semen of just one stallion, which is impressive on the parts of both the scientist and the horse.
As is inevitable when you're at the top of your game, the mind starts to wander and you look for new challenges to keep you entertained. For Ivanov, it was getting the sperm of animals and putting it into different species to see what happened.
He started off slowly, creating a zedonk (from a zebra and a donkey), a rat-mouse (self-explanatory), a guinea pig-mouse, and some abomination made from an antelope and a cow.
Then, in 1910, he told a gathering of zoologists that he thought it could be possible to create a human-ape hybrid, often now referred to as a "humanzee". At the time it was merely hypothetical, like biologists today guessing what aliens could look like, or astronomers suggesting a date when the James Webb Space Telescope will actually be launched.
Ivanov wasn't the first to dream this, and he wouldn't be the last. Though realistically such a hybrid would be incredibly unlikely to make it to term, there have been claims of human-ape hybrids long after Ivanov's time. One such animal was Oliver the chimpanzee who walked upright and was touted by his promoters as a hybrid, that was until scientists proved it not to be the case.
His chance finally came after the Russian revolution of 1917 while working at the Institut Pasteur. It was here, in 1924, he was given the opportunity to work on the hybridization scheme of his dreams. The man - who is the last person you'd want near chimpanzees - was told he could have access to all the chimpanzees he liked in a facility based in what was then known as French Guinea.
Amazingly he received $10,000 from the Soviet Financial Commission to carry out his work, before securing the approval of the Soviet Academy of Sciences, as well as senior members of the Bolshevik government.
In his pitch, he stressed that it was an experiment that could prove Darwin's theory as to how closely related to apes we are, which would be a blow against religion. It's also possible that the Bolsheviks were keen on showing what could be achieved through genetics, which fit in well with their idea of "positive eugenics".
He arrived at the facility to do what he did best: transferring semen from one animal to another. In 1926, he and Serge Voronoff transplanted a human ovary into a chimp, before attempting to inseminate her with human sperm. He attempted this two more times without success.
You might have hoped at this juncture he'd admit defeat, but instead Ivanov pitched an alternative (and considerably more horrific) approach: to take sperm from chimpanzees and implant it into African women without their knowledge or consent. The plan was to pretend that the insemination of a chimpanzee was merely a medical examination, letting them find out months afterwards when they gave birth to an exceptionally hairy and suspiciously good at climbing baby. Thankfully, the French governor said no to the idea, and he traveled to Abkhazia, with 20 apes in tow.
He still wasn't done. One way or another, he intended to get himself a hairy humanzee, so he began recruiting Soviet women who were willing to do their half for science. Amazingly (again) - and it really would be amazing to see how this guy pitched, humanity clearly lost a great ad man to unhinged ape experiments - he was able to convince people to go along with it.
Five women or more volunteered for his experiment. Un/fortunately, no apes survived long at the ape nursery and, though he had women, he found himself out of sperm. Before he could ship in more, the Soviet Academy of Sciences heard about his plans to inseminate women in Africa without consent, and all support for the project was taken away on the grounds that it "[M]ight undermine the trust of Africans in European researchers and doctors and make problematic any further expeditions of Russian scientists to Africa".
Before he found a new way to carry on his work, he was exiled in an unrelated purge of scientists by the government and died soon afterwards, completely monkey-manless.