This uneasy feeling is due to the "uncanny valley": the strange place on the continuum between fake and real human that gives you the creeps. In 1970, the Japanese robotics engineer Masahiro Mori noticed that the more human-like the robot, the more appealing they are to people—to a point. Once they look too much like a real human, people get uneasy.
The fear of dolls, pediophobia, lies under the "uncanny valley" umbrella of phobias called automatonophobia, or a fear of things that look like humans. This fear can encompass other objects, too, such as robots, wax figures, and statues. Like pediophobia, the more lifelike the inanimate object is, the creepier it becomes. In the videos below, learn about more unusual phobias and why we find things creepy.