Circus Baby/FNaF World

Circus Baby isn't a playable character in FNaF World, but curiously, it's the game she first appears in.

History
In Update 2, after Chica's Magic Rainbow's defeat, the player will be sent to Desk Man's house. He will mention he's made something terrible, and refers to her as simply Baby. He says it's too late to deactivate her before the room turns pitch black, with two yellow glowing eyes seen at the top right. The player will hear Baby's voice for the first time, as she says the show will begin momentarily, the room will fade back to normal, with the man bleeding out at his desk. The game fades to black, and ends with a message saying "to be continued...", which might have either been a teaser for the then upcoming Sister Location, or a scrapped update.