Baby

Circus Baby, also known as just "Baby", and originally known as Elizabeth Afton when she was still alive, is the primary antagonist of Five Nights at Freddy's: Sister Location. The soul of William Afton's daughter resides within her alongside Baby's own consciousness. In Night 5, she removes her endoskeleton from her costume, and her fellow animatronic cohorts, so she can combine them to create Ennard.

Appearance
Baby appears to be a humanoid jester or clown animatronic. She wears a skirt and wields a microphone. There are pins in her arm and she has either a orange hat or ginger hair with pig-tails. Her face, like every other animatronic, is segmented into separate parts that move to make different expressions. She has red cheeks, lipstick and a red nose. She has almost human green eyes, that sometimes glow, and both eyes have four eyelashes. Her face is white.

In FNAF World, Baby is hidden in the darkness and is said to be created by the Desk Guy. She has yellow eyes that glow in the dark, and that's all we can see of Baby.

Trivia

 * Only animatronic without a jumpscare
 * Surprisingly, Circus Baby doesn't have an actual jumpscare in the game, but has a jumpscare in the trailer.
 * This may be what it looks like when Circus Baby receives a controlled shock.
 * This may also be Circus Baby being scooped, though this is unlikely.
 * Circus Baby is the leader of the animatronics, similar to Freddy from previous games, however her main objective is to devise a plan to escape the facility, rather than killing the player.
 * On Night 1, the lights in Baby's stage area may have been intentionally turned off so the player would be forced to shock Baby repeatedly despite her behaving normally.
 * Ennard's endoskeleton can be seen waiting behind Baby on night 5 to attack the player after sending Baby to the Scooping Room.
 * From the Memory Dialogue, Elizabeth says that the animatronic was made just for her, hinting that Circus Baby was made in the daughter's image or to look the way his daughter wanted her to look like.
 * Circus Baby shares a striking resemblance to the little girl with red pigtails in FNaF 4, which has lead people to theorize that she is William Afton's daughter.