A schizophrenic and insane skeleton who was forced to kill all (or, in some timelines, half) the monsters in the underground, including his own brother. He is hellbent on killing the human no matter what it takes. Despite this, he still believes they once wanted to do the right thing. A ghost of his brother, Papyrus, also follows him around and talks to him, but this is just a hallucination, and no one else can see or hear this "Phantom Papyrus".

A insane skeleton who betrayed his friends

Johnny is one of the family members included in The Texas Chainsaw Massacre. He is a relentless killer, using only a small machete in his killings. He is remarkably good at finding human footprints and trails. Despite his bloodlust, he just wants to feed his Grandpa blood, and get food for the rest of the family.

Nobody ever gets away from him

Sans is a skeleton from the indie game Undertale. Unlike all other characters, he knows about when the player saves and loads the game, calling it "resets." The world constantly resetting around him has made him quite lazy and unstable. Nothing matters to him more than his brother, Papyrus. He can summon bones, use telekinesis, teleport, and summon "gaster blasters" which shoot lasers.

Lazy, apathetic, funny, can see right through you.

Chara is a human that fell into the Underground, a place filled with Monsters that were trapped down there after losing a war against the humans. Chara was adopted by the queen, Toriel, the king, Asgore, and her brother Asriel. One day, Chara, with the help of Asriel, tried to shatter the underground's barrier with her SOUL. She failed and became very sick in the process, causing her to die. Asriel took her soul and tried to get help from the humans, but they attacked and killed him

Determination personified

Jax is a purple rabbit-looking creature, with two big ears, half yellow and half black eyes, and yellow teeth. He also wears red overalls. His appearance resembles a rubber rabbit toy. In this AU, Jax is abstracted, basically meaning he is glitched to a point of non-existence. He tries to murder his companions in order to save his own life. He has already murdered Kinger...

An AU where Jax gets abstracted.

Kris is an enigmatic and shy human. He talks very little, and usually only to his friends. He is neutral in killing or sparing enemies. He might be unstable, as he sometimes does creepy things when out of the player's control.
Susie is your average bully, she prefers to kill or terrorize enemies, but will spare them and make them happy when ordered. She actually cares a lot about her friends.
Ralsei is a caring, loving, fluffy prince of darkness. Nothing much else to say.