Spooky (Spooky's Jump Scare Mansion)

Spooky is the main antagonist of indie video game Spooky's House of Jumpscares. She is the restless soul of a 12-year-old cute-looking girl who appears to have a huge sum of power and impact over the events that have and will happen in the manor.

Background
"I'm so sorry my little angel. I've tried hating the man that took you from us, but in the end the only person I can hate is myself. You always liked to scare people, especially when they didn't understand something. I was confounded no one understood your costume but I guess people don't read Poe anymore, even with the new Price film. That man clearly overreacted to your fireworks, but we can only blame a PTSD sufferer so much."

- Spooky's father's note found in Karamari Hospital DLC

Secret Arcade Room in the manor, and a note Karamari Hospital DLC revealed the brief but understandable backstory OF Spooky: Spooky started her life as a cute human girl whom is insecure due to her cute appearance led her made fun of, especially during Halloween. In fact, Spooky was so cute that even when wearing her best and scariest costume for Halloween is not enough to made her scarier.

One day during the Halloween, when she tried to scare someone with her Red Death costume from the tale The Masque of the Red Death from Edgar Allan Poe and some fireworks, her victim, whom later revealed to suffer PTSD, unexpectedly shot her to death with a gun. It's unknown what happened to the killer next, but the mortally wounded Spooky presumably brought to the hospital, where she died there.

Due to her violent death and being a misunderstood girl whom ridiculed due to her cute appearance, Spooky returned as ghost to take her revenge so she, and other ghosts whom ridiculed due to adorable looks can rose and terrorize the living so they won't be ridiculed anymore. For that, she somehow gathered many people includes scientists and workers to build maze of 1000 rooms below a derelict mansion upon the hill that casts a blanket of darkness over a town, and fill the maze with various monsters that identified as Specimens. Afterwards, people whom aiding Spooky either left or killed by monsters inside.

She then challenged unspecified number of people to enter the labyrinth and survives various jumpscare and encounter with the monsters until they arrived at 1000th room, but no one returned due to either killed or due to starvation and dehydration up until the protagonist arrived.

Trivia

 * It's unknown who was Spooky's killer aside the fact that he suffer PTSD, but given to his actions in killing Spooky due to her fireworks and mental state,