We’ve made leaps and bounds in the field of robotics. From picking bots taking over the floors of Amazon’s warehouses to helping doctors perform cochlear implant surgery, robots are becoming an essential part of our existence.

But when it comes to creating robots that resemble and interact with humans, things get a little more complicated. And by complicated, we mean creepy. While some researchers are eagerly charting the course towards A.I. that will resemble and even act like us, their creations thus far still manage to elicit a shudder from everybody who interacts with them. It’s known as the “uncanny valley,” a term used to describe the feeling of revulsion we all seem to experience when we encounter something that replicates the quality of being alive.

But like a car accident, it’s kind of hard to turn away. With that in mind, here are five of the most amazing — and terrifying — lifelike robots.

Sophia

Sophia is a robot designed to look like Audrey Hepburn by Hanson Robotics. She has shockingly vivid facial reactions, can tell jokes, and is capable of spontaneous conversation. The idea is that a lifelike robot like Sophia will be able to function in human interaction roles like customer service, healthcare, and education. She has cameras in her eyes and is programmed with algorithms that allow her to see faces, and she can remember interactions. This will all allow her to “get smarter over time,” according to creator David Hanson.

Motormouth Robot KTR-2

Okay, so this is just a creepy mouth, but this robot developed by researchers at Kagawa University in Japan makes human-like sounds via robotic vocal cords that function the same way as human vocal cords. The mouth and tongue are made from silicon rubber, and it has a nasal cavity that helps it to pronounce “m” and “n” sounds. It can also hear itself, and it learns through auditory feedback to determine what motions it needs to develop to sound more human-esque.

Geminoid

Built by Hiroshi Ishiguro Laboratories of Osaka, Japan, the Geminoid is a hyper-realistic robot modeled after its own creator. Operating it remotely, Dr. Hiroshi Ishiguro talks about how he could send his robot avatar to a conference in the U.S. or have it teach a lecture somewhere he can’t be. “The importance is my presence is there,” he says. If you say so.

Erica

Professor Ishiguro has kept busy since designing Geminoid. He also created Erica, an android who relies on A.I. for her responses to human interactions. Her design function is to operate as a receptionist or a personal assistant, responding to simple commands and conversation. Earlier this year, The Guardian made a documentary about her intelligence evolution and the philosophy around developing a robot that’s so lifelike.

Harmony

This really wouldn’t be a proper, realistic A.I. list unless we mentioned the sexbots. Harmony A.I. is an anatomically detailed silicone doll. She comes with a robotic, responsive head that you can program with certain personality traits via your phone. The robot is not actually up for sale yet — Harmony is slated to be on the market early next year — but her prototype is freakishly lifelike and much less threatening than other A.I. robots. There’s a reason for that. Matt McMullen, Harmony’s creator, has a lot of experience in creating enticing fake humans; he’s also the founder of Abyss Creations, the manufacturer of RealDoll.

If you liked this article, check out this video of thought-controlled robots from MIT.