In the Undertale AU, Error Sans is the destroyer of AUs, in opposition to Ink Sans. He is insane, bent on destroying everything he considers a glitch in the multiverse, using blue string to tie up and shatter souls.

In the Undertale AU known as Underswap, Napstablook is the one who end up as a robot called Napstabot, instead of Mettaton.

Underfell Sans is special kind of special, a murder-y kind. He enjoys long walks on the beach and inflicting pain on the human. Being pushed around by his brother Papyrus, this is a given.

In Undertale, Alphys is the scientist who helps Frisk find her way through the Underground. She’s a dinosaur-like monster who loves anime (and Undyne) and she’s very shy and doesn’t have much confidence in herself. She usually wears glasses and a lab coat, but if you wish to cosplay her dating outfit, she wears a black dress with white polka-dots.

In Undertale, Papyrus, also known as COOLSKELETON95 on UnderNet, is the brash younger brother of Sans. He wears a custom-made “battle body” costume and wants to catch a human so that he can become a member of the Royal Guard. Mom’s spaghetti.

In Undertale, Burgerpants is an employee at the MTT-Brand Burger Emporium, a fast-food restaurant located inside MTT Resort. He is a 19-year-old orange cat-like monster who wears a small hat with the letter M on it, as a part of his job working for the MTT-Brand Burger Emporium. Burgerpants is a highly stressed-out service employee, who hates his job and his employer.