In Undertale, Undyne is a fish-like monster that leads the Royal Guard. Clad in her full armor, she pursues the protagonist through the entirety of Waterfall, frequently evaded or inadvertently thwarted by the Monster Kid. She has blue scales and a long bright red ponytail. She has red and blue fins on the side of her head, and a pair of sharp yellow protruding teeth. She wears bright red eye shadow and has an eyepatch on her left eye. Her eyes have vertical black pupils and a yellow sclera.

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, 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 a certain Undertale AU, Underswap, where two character’s identities are swapped. Underswap Sans has the personality of Undertale’s Papyrus. Sans, known as “Blueberry”, is the younger brother of Papyrus and a major character in Underswap. He is agreed, by many, to be adorably cute.

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.

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.