cutesytale is an au where everything in the au is cute.

undyne still wore a suit, but it was decorated with flowers and hearts by monsterkid (who is a female and undyne's daughter)

sans had gained a huge hole in his head from the third human that fell down to the underground, so he wore a bandage across his left eye

all the monsters were happily living in the underground, until one day a human fell in the underground