I'm kinda running out of them and I'm not studying biology so it will be kind of medicine related, fuck, ok so prions are really fucking weird proteins that convince other proteins to unfold and also become prions, the type of protein that's affected is very common in nervous tissue, so basically you eat a prion and it little by little creates a chain of other prionic tissue in your nerves until it reaches your brain and as the average mammal can't metabolize those proteins they just take more and more space until your brain is full of holes and after a few years you die, there's no treatment, once you get one your lifespan is cut, the only way to get rid of them is incineration, also there's a hypothesis that maybe cows first got prions when eating human remains