River Styxx is the daughter of the Grim Reaper and a student of Haunted High in the Monster High franchise. She attends Haunted High, a school for ghosts. She appears in the TV special Haunted.
River Styxx is voiced in English by Ashley Peterson.
Unlike the traditional version of the Grim Reaper, River is extremely cheery, upbeat and bubbly, and loves bright colours and candy. She has a lot of energy and finds it hard to concentrate and stand still. Although, she does get evil feelings to scare other monsters
She loves to make people laugh and smile, and is always telling stories, planning parties and fun events for others, particularly the spirits she and her father transport to the Ghost World.
River is a Reaper In Training, (R.I.P) which means she is only allowed to carry a staff around instead of a scythe. Due to her Grimm Reaper heritage, River also carries a mysterious aura around her, and owns the ability to change her voice, the environment arounde her, like the sky, and she will one day be able to perform reaper's work, and pursuit all powers a reaper should have.
River has purple skin, which is transparent on her lower limbs so that her bones are visible. Her hair is blue, pink and purple. She has ghostly big blue eyes and, because she has both ghost and skeleton traits, visible lines on her mouth, to represent teeth, visible eye orbits and skeleton nose. She is short.
River's father is the Grim Reaper, one of many responsible for transporting passed on ghosts and spirits to the Ghost World. He has a hard time dealing with his daughter, who is not what a reaper is expected to be. As a result he might be a little strict on her.
In her diary, she mentions her father has a cousin, a former reaper who broke the rules and was punished by being banished to the real world, and now works as a high school guidance counsellor. It's highly implied this cousin is Mr D'eath. Her Uncle is Charon, the ferryman of the dead in Greek mythology.
She has a skeleton raven, Cawtion.
- January 22, 2014: Mattel requests the trademark for River Styxx.
- April 9, 2014: Mattel requests the trademark for River.
- July 26, 2014: River Styxx's debut doll is on display at San Diego Comic-Con International.
- March 25, 2015: River Styxx makes her 3D cartoon debut in "Haunted".
- Her name comes from the river Styx, the river which separates the realms of the living and of the dead in Ancient Greek mythology.