It all starts innocently enough, you are clearing out cobwebs when a spider falls onto your neck and bites you. Assuming you don't manage to squish the spider immediately you get a good look at the small thumbnail sized thing. While normally vile and gross, this particular spider seems cute to you. Naming it appropriately you decide to keep it as a pet in a jar, cute little guy.
Squish it or not you will soon find most spiders not repulsive, but anger inducing. All spiders except spiders that look like that awesome little guy that bit you. You keep him well fed and protected as your cool new pet. In time he grows bigger and bigger. Eventually the spider becomes worthy of your respect and praise.
In time you bring others over to see you pet, and in careful conditions he may bite them too. "He only bites you if he likes you!" you may say if he's small. Or "It will make sense, don't fight it" if it has reached rodent sized proportions. You and others like you will want to settle down and have kids, probably somewhere quiet and secluded, away from the hustle and bustle. Some of these kids may be born with unusual mutations, not many, but some. Adorable spider features, from the good kind of spider like your spider friend, not those evil other spiders.
Perhaps they are some sort of centauroid spider, or have the head of a spider, or multiple limbs. Perhaps just the head of a baby on a spider's body, either way they are cute members of your little family. Of course if your spouse wasn't made a friend of your spider friend, leader of your new wilderness community, they may "freak out" and try to do harm. They sadly may need to be dealt with lest they rouse any neighbours who just don't understand.
And your spider friend has truly grown large, bigger than a cow and growing! Truly a sign from the gods worthy of praise and adulation! let others worship your friend and the good fortune it brings! Many generations may go by, or just one as the mutations don't always happen and can go generations down the blood line without manifesting, a special bundle of joy will arrive. One pregnant host will give birth to the next generation! to the joy of the midwife (assuming they are part of your true community), thousands of new baby spider friends will be born in a great swarm from one lucky mother! They will be able to be spread out and go to the far corners of distant lands, until somewhere...
someone is clearing out cobwebs..when a spider falls onto their hand and bites them..
This type of cult or monster is a great way to freak the hell out of players on so many levels. It is also a good way to throw entities like Llolth in a new light, and just why it is that Dark Elves ran underground and are full of half drow/half spider mutants.
Mmmmm...Rich Creamy Vanilla
3 hours ago