Tesla's humanoid robot will one day be the most valuable part of the company's business, CEO Elon Musk predicted on Wednesday.

Musk said on Tesla's first-quarter earnings call that the importance of the robot, dubbed Optimus, "will become apparent in the coming years."

"I was surprised that people do not realize the magnitude of the Optimus robot program," Musk said Wednesday evening. "Those who are insightful or who listen carefully will understand that Optimus ultimately will be worth more than the car business and worth more than full self-driving. That's my firm belief."

Musk said that the first models of the bipedal robot would arrive next year, though experts are skeptical about that timetable. Musk is known for giving overly optimistic predictions. He is years behind schedule on a 2016 promise that Tesla would deliver self-driving cars since by 2017, and recently said that Tesla is "not currently working" on a $25,000 self-driving vehicle that he said in 2020 would launch by 2023.

Here's what we know so far about Optimus.

It is meant to perform repetitive tasks

Musk first announced the robot last summer at Tesla's AI Day, a series of tech talks hosted by the company to recruit machine learning talent. In the announcement, Musk brought an actor dressed in a body suit designed to look like the robot onstage and had him dance for the audience.

Musk said the goal was to create a machine that could drive labor costs down.

"It's intended to be friendly, of course, and navigate through a world of humans, and eliminate dangerous, repetitive and boring tasks," CNBC reported Musk saying at the time.

Musk said that he envisioned a future where the robot could run errands for its human owners as well.

"It should be able to, you know, please go to the store and get me the following groceries, that kind of thing," he said.

It won't pose a threat to humans

Musk, who in the past has warned about the dangers of artificial intelligence, also said that the robot was being designed so that humans will be able to outrun it or overpower it were something to go wrong.

"As you see Optimus develop, everyone's going to make sure it's safe," Musk said earlier this month. "No Terminator stuff or that kind of thing."

The robot will be five foot eight inches tall and weigh 125 pounds, Tesla said. It will carry a maximum of 45 pounds, lift 150 pounds and will move at a maximum speed of 5 miles per hour. Its face will be a "screen for useful information."

Musk believes Optimus is Tesla's 'most important product'

Musk earlier this year ranked Optimus as a higher priority than other hotly anticipated Tesla products, including the Cybertruck pickup and the Tesla Semi.

It remains to be seen if Tesla will be able to deliver on Musk's promises, however. Gary Marcus, an AI researcher, told CNBC this month he was skeptical that Optimus could live up to the hype by 2023.

"Tesla has not even (after years of effort) come close to reliably solving one relatively simple task (driving); to claim that a robot that has never been shown publicly will solve all of human tasks in the next year or two is preposterous," he said.

Sign up now: Get smarter about your money and career with our weekly newsletter

Don't miss: Use this calculator to see how compound interest can help your money grow over time