oooh ooh! this is my thing:
Phant fact number 1:
Faun horns are made of keratin, just like fingernails. So when fauns want to hide their horns or pretend to be human they can file them away or cut them. It doesn’t hurt, and they’ll grow back, but, again, like fingernails, it’ll take a while.
Also, it’s just a real pain to try to file them away with an emery board, and nail clippers are never ever big enough for that, so they have to use a special kind of serrated blade sort of like a little bread knife. But for horns.
Phant fact number 2:
Mermaids are, in fact, venomous. Their venom is a neurotoxin and an irritant. They can’t make this venom on command, it is part of their body’s panic response and is a variation of their saliva that happens when they believe they are in danger.
They can use this venom by spitting it onto people, in which case it will burn, not like acid, but like when you get spicy pepper juices on your skin. And if this venom gets inside your body it will paralyze your lungs. They don’t have to bite you for this to happen, you’ll be paralyzed if it makes its way into our mouth as well, but the reaction will be slower. So basically no spontaneously kissing a mermaid without her permission unless you literally want to die.
Phant fact number 3:
Fairies can hold onto a pregnancy as long as they like.
Fairies have the ability to keep a fertilized egg in their womb dormant for an indefinite period of time. Even decades. They can decide on their own body temperature at will, and by keeping it cool enough, they can keep the egg in a sort of stasis where it will not grow into a fully developed child ready to be born unless the mother wants it to. This is a tricky balance though. Naturally, if left to their own devices their bodies will automatically stay at a temperature appropriate for the gestation of the child, but if a fairy is not extremely careful, she can make her body either too cold or too hot while trying to keep the egg dormant, thus making her body inclement.