Elon Musk’s brood has grown to 11.

The tech giant secretly welcomed a third child with Grimes, named Techno Mechanicus, according to a book review published by the New York Times Saturday on Musk’s soon-to-be-released biography, “Elon Musk.”

The outlet briefly mentions Musk’s child with the “Genesis” singer, whom the former couple has affectionately nicknamed “Tau.”

Very little is known about the little one or when the kid might have been born.

Musk, 52, and Grimes, 35, share two additional children, 1-year-old daughter Exa Dark Sideræl — whose nickname is “Y” — and 3-year-old son X Æ A-12.

In May 2018, Page Six exclusively reported that Musk and Grimes had begun dating.

A source told us at the time that the two met after the Tesla founder intended to write a joke via Twitter about artificial intelligence, but found out that Grimes — born Claire Elise Boucher — had already made the same joke.

The couple welcomed their first child, X, two years later in May 2020.

The billionaire businessman and the Canadian singer then welcomed their second child, Exa Dark Sideræl, in December 2021.

The duo called it quits just a few months after their daughter was born via surrogate.

“Me and E have broken up again since the writing of this article haha, but he’s my best friend and the love of my life, and my life and art are forever dedicated to The Mission now,” Grimes wrote via Twitter after the fallout.

While it is unclear if the two have gotten back together, the musician and Musk were spotted in Portofino, Italy, in July with their son. Although the two were not photographed together, a source told the Daily Mail at the time that they were staying at the same swanky hotel.

Musk’s son Saxon, 17 — whom he shares with ex Justine Wilson — was also present during the vacation.

Earlier this week, Grimes pleaded with Musk to see her son in a since-deleted tweet.

“Tell Shivon to unblock me and tell Elon to let me see my son or plz respond to my lawyer,” she wrote. “I have never even been allowed to see a photo of these children until this moment, despite the situation utterly ripping my family apart.”

The X, formerly known as Twitter, owner shares 11 children with three women.

Musk is a dad to son Nevada with Wilson, however, the couple lost the 10-week-old to Sudden Infant Death Syndrome (SIDs).

Wilson and Musk would later welcome twins, Griffin and Vivian, in 2004.

In January 2006, they also welcomed triplets Kai, Saxon and Damian. Musk and Wilson divorced two years later.

The billionaire also secretly welcomed twins with Neuralink director of operations and special projects, Shivon Zilis, in November 2021 — just before Grimes gave birth to her second child with Musk.