weird things about prions

they reproduce without exchanging genetic information; indeed, they have no genes

they can be transmitted vertically, between mother and offspring, or horizontally, between unrerlated members of the same species

they can be transmitted between different species

when they are transmitted between species, they can change according to the new host's system, and then reproduce with those changes, ala Lamarckian evolution

they cannnot really be destroyed by heating, freezing, radiation, or solvent. total incineration is the only known way to get rid of them

there's a whole range of the kind of diseases they can produce, depending upon the host's genetic makeup. one of the most creepily poetic is called Fatal Familial Insomnia, an inherited disease, in which people die from not sleeping. even barbituates do not allow them to sleep.