Tesla CEO Elon Musk says his company is working on a humanoid robot and that it will build a prototype “sometime next year.” The humanoid robot will leverage Tesla’s experience with automated machines in its factories, as well as some of the hardware and software that powers the company’s Autopilot driver-assistance software.

Musk, who has spoken repeatedly about his fears of runaway artificial intelligence, said the Tesla Bot is “intended to be friendly,” but that the company is designing the machine at a “mechanical level” so that “you can run away from it, and most likely overpower it.” It will be five feet, eight inches tall, weigh 125 pounds, and have a screen for a face. The code name for the bot inside the company is “Optimus,” he said.

The robots will be designed to handle “tasks that are unsafe, repetitive or boring,” the company’s website reads, but little else, at least at first. (There, the bot is simply called “Tesla Bot.”) “I think essentially in the future, physical work will be a choice, if you want to do it you can,” Musk said.

Musk revealed drawings of the robot near the tail end of his company’s “AI Day” event, where it showcased some of the artificial intelligence and supercomputer technologies that it’s working on with the goal of one-day powering self-driving cars. The company also had a mannequin version on the stage, which wasn’t working.

Tesla’s history is littered with fanciful ideas that never panned out — like a solar-powered Supercharger network, battery swapping, or robotic snake-style chargers — so it’s anyone’s guess as to whether a working Tesla Bot will ever see the light of day. But the company is where it is today because of Musk’s sheer will. Asked about the near-term economics of entering the robotics industry, though, Musk said “we will have to see.”