(Literally an AU where all of the characters are smaller than the size of your palm.)
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(Idea created by; @SansSkeleton and @PapyrusTheSkeIeton .)
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(jeez we made so many AUs together didn't we? holy spaghetti)
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(Anyway, we just made this AU for fun. May be a serious thing soon. >w<)
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(Also, they may be the size of shimejis. Don't know what they are? Just look them up, or ask in the comments.)

Bio's (this isn't a rp group):

Sans
Height: 2 inches, 5 centimeters
Weight: About the weight of a pencil
Favorite food: Hotdogs smothered in ketchup
Personality: Sans likes just chilling out with his bro and whoever cares for him. He'll just sit on your shoulder or sleep inside your pocket. He'll also help you with your math homework. Oh, and he's a prankster.
Rules for caring for Sans: Don't try to take Papyrus away from him, or he'll probably break your finger. You must feed him one little drop or ketchup a day, or he'll most likely die. Sans will want to follow you around, so just let him. He sleeps whenever he feels like it. Don't wake him up.
~ @SansSkeleton
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THE GREAT PAPYRUS!
(He still believes in you!~)
Height: Three inches.
Weight: Similar to an Eraser's.
Favorite food: SPAGHETTI, OF COURSE!!
Personality: Pretty much the same as the Papyrus ingame, but with a few differences here and there; He is (Slightly) less self-obsessive. (But he still is.)
And will be more joyful than usual from time-to-time. He STILL hates Sans' puns and jokes though. What's the fun in having a non-easy-to-upset-when-it-comes-to-a-certain-situation-like-jokes-being-said Papyrus? And he's pretty Agile(Stealthy).
He likes to spend time with his friends and brother a lot. Papyrus can do many things, including chores(However, they HAVE to be small chores. Like putting simple, non-heavy stationary equipment in a case. I mean, he's tiny.)
[ *Papyrus' BIO writer ran away. ]
~ @PapyrusTheSkeIeton

Undyne
Height: 3 inches, 6 centimeter
Weight: Slightly lighter than one of those big erasers
Favorite Food: Not sure. Let's go with...sushi. (Heheh)
Personality: Undyne is very similar to her in-game self. Only she's a bit less hotheaded, which is good, or all your fingers would be broken pretty quickly. Undyne also likes to pick up pencils and pretend that they're spears. She likes hanging around Papyrus and Alphys, and is very protective of both of them.
Rules for caring for Undyne: She can actually go many days without eating, but you must feed her something at least once a week, preferably a 5 by 6 chunk of meat. She likes sleeping in shoes, odd enough and will often throw things if she gets mad, so keep your textbooks away from her.
~ @SansSkeleton

Alphys
Height: 2 Inches
Favorite food: Anything which is considered to be Anime-Related. Like Japanese Noodles.
Personality: Seemingly enough the same as the Alphys in-game(Like a few of the others), except she's more worried about things. Especially being crushed by humans.(Yes. The humans in this AU are huge, like real people.) She dislikes it when people remove her glasses, but she cannot get enraged about things.
She also likes spending time with Undyne. However- Moving onto the Upset topic- If she WERE to be upset, her voice would be slightly squeaky. She still stutters, though.
And on her FIRST prototype on MTT, He was literally a calculator.
LITERALLY. NOT EVEN JOKING. (But after finding a bunch of materials that have been broken from things, she managed to make him a small version of the literal MTT.)
~ @PapyrusTheSkeIeton

(More coming soon, y'all.
~ @SansSkeleton )