In a certain Undertale AU, Underswap, where two character’s identities are swapped. Underswap Papyrus has the personality of Undertale’s Sans, but the look of Papyrus. He’s just pretty cool.

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

In Undertale, Grillby is a quiet fire monster who owns and runs the bar Grillby’s in Snowdin, where Sans is a regular.

In Undertale, Sans is a short and big boned skeleton, with a perpetual grin on his face. He wears an unzipped hoodie, a white t-shirt or sweater, black shorts with white stripes and a pair of sneakers or slippers. He has white pupils, which tend to disappear when he is serious. When fighting, his left eye flashes cyan and yellow and his right pupil disappears.

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 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.