A baby boy named Elon Musk has been born at home after his mother rushed him into labour.
Elon Musk, 42, was born to his girlfriend, Jessica Simpson, at home on January 10.
The couple have a daughter, Sophia, 11.
He was born weighing just 1.8lbs, but he was given an electric car seat by his mother and has a 2lb, 3oz baby shark strapped to his chest, which is attached to his heart.
His mother said he had been feeling better and was happy.
Ms Simpson is the sister of actress Jennifer Lawrence and the brother of actress Jake Gyllenhaal.
She is also a mother of twins, who were born on January 8.
“The family is extremely happy, very much so,” Ms Simpson told the ABC.
Mr Musk is an investor in Tesla Motors, where he has an estimated net worth of $5.5 billion.
Musk said the family were delighted with the birth.
“He’s doing well, and we’re very happy with that,” he said.
“We’re not doing very well, but it’s nice to be home.”
He is also an avid cyclist and is a strong believer in the value of the earth.
A number of people have donated to his cause through a crowdfunding website called Crowdrise, and he also raised money for children with special needs through the Musk Foundation.
In the lead up to the birth, he said he planned to go on a bike ride in his home state of California.
“I’m going to do a little bike ride around here, but then I’ll go to Florida,” he told reporters.
Last month, Musk told the New York Times he wanted to make his own solar power system to power the world.
Earlier this year, Musk said he would build a car with a retractable roof for $20 million.
After the birth of his son, Mr Musk said it was a huge honour to have a baby boy.
“To be here is very special.
This baby was a big dream, and it’s been an honor,” he added.”
It’s been a big journey, but I’m not sure I’d change a thing.”