In the year 2020 a group of scientists work in a lab to find a cure for COVID- 19 by combining DNA with various mammals and jelly fish. Soon their experiments prove successful and their vaccine is distributed world wide to everyone thus ending the pandemic. It was not until a year later that the side effects were revealed.
In the summer of 2021, without warning everyone in the world started to melt. Or more accurately, everyone turned into slime.
Everyone that received the injections body became transparent, and melted into a puddle. Another odd thing, was the fact that humans also gained the ears and tails of various animal species seemingly at random. These animal ears and tails are always present in any form they take, even when they are a puddle. Along with that, once people learned how to manipulate their slime bodies into humanoid shape, they also were now incapable of any non female humanoid form. Over the years humanity learned more of the “rules” of their new slime animal female bodies.
Aside from anything overly masculine (the best people can do is tomboy) people now have full control over their bodies. Able to shape their slime mostly however they want aside from removing their ears and tails. Some people prefer to be slime puddles, others embrace their animal traits shape shifting their bodies to match their ears and tails and living in the wild, some stay in a humanoid female form, a few even buying clothes, and some even still change their appearance to be full anthro with muzzles and paws.
Slimes only have 3 organs, the two eyes and the “slime core” aka the “nucleus”. A sphere about the size of a base ball that produces slime and is were the mind is kept. Some prefer to keep their cores in their chest, others their heads.
Your color is determined by your mood at that moment.
As far as anyone can tell, slimes are seemingly immortal so far. As long as nothing happens to their core.
Slimes are capable of fussing together to form one body. If this fusion last long enough (time varies but generally it’s a year or more) then their cores will actually start to combine as well making them one singular slime permanently. With their memories now shared.
Slimes can divide like cells, though afterwards each slime is only half the originals size. They start off with identical memories and personalize to eachother but as time passes their different experiences will gradually make them into different people.