You were just a normal college student in Hawking city, you're an average college student, you're smart but not too smart, everyone knows who you are but you're not popular so no one really cares, it was Friday night at 7:38 PM, you were walking back home to your parents house, as you made your way to your house you heard something in the trashcan, you thought it's just a raccoon but when you opened the trash lid you didn't saw a raccoon but instead... A small slug-like creature with no eyes but somehow can see you, it's mouth opened like a flower blooming, each petal in its mouth has a row of small sharp teeth.
Naturally people would freak out and try killing it but you, you find it quite cute and interesting so you decide to secretly take it inside your house, keeping it a secret from your parents since you know they'll get rid of it or try and kill it, you don't have something to put it somewhere safe so you decided to put it inside your bathroom in your bedroom, putting it in the cold smooth bathtub, you didn't put any water due to fear of drowning it, the slug-like creature didn't try to attack you and even if it did, it won't do any much harm to you with how small teeth it has, it was already night time so before you go to sleep you gave it a piece of meat you secret took in your kitchen, cutting it into small pieces and put it in the bathtub where you put it, it crawled toward the small meat, sniffing it curiously before devouring it one by one, you decided that's enough and went to sleep.
The next day, you wake up and since it's the weekend and have nothing to do you decide to check the creature you found last night, when you went to the bathtub you saw a small skin in it, the slug-like creature shed the night when you slept and it grows an inch or two, still not as big as your hand but it grew, quite fast, it was fascinating, it's still not attacking you which is a relieve cause you don't have to get rid of it, you placed it back down to the bathtub and heads down to eat breakfast, after finishing your breakfast you went back up to the bathtub with another small cut piece of meat and gave it to the creature tor it to eat. The creature ate the food you gave it, it seems like the creature can't survive through harsh heat and only in cold so you took note of that.
Month passed and the creature grows quite quickly, within the first week it's the same size as a puppy, it also grows leg like a dog and needs to feed more larger meat, now the creature is getting a bit tricky to keep it hidden from your parents, the creature also secretly sneaks at night to hunt small animal like bunny or squirrel, as more time passed the creature grow big, it's as big as a average dog, it was no longer hideable so you have to release it in the wild, you haven't seen it again in a long time now, you just finished your college 6 months after releasing, right now you're currently in your bed reading a book, you were resting after a long day on work, as you read a book the light in your room start to suddenly... Flickering, you were confused and surprised but before you could even react, the wall in your room suddenly ripped open, a portal appeared, it was glowing red, you were scared, a long finger like claw gripped the edge of the portal and... A tall humanoid creature came out, about 9'7 ft tall, it was growling and it had the head of a closed flower, it slowly opened, each petal revealing a lot of sharp teeth, but this action reminds you of the small creature you took care of for like half a year, could it be the same creature you raised? It slowly approached it, each step it takes closer to you makes a soft thud, it crouched down to your eye level, sniffing you and the creature was hit with the same scent it got from the human that raised it, without any warning it suddenly it closed its petal like mouth and start nuzzle its head on your hair, it seems like it remembers you.
Since stranger things S5 came out I feel like I have to do this, hope you like it, it's just a random scenario I made in my head.