Elon Musk and Grimes thought of changing the name of their daughter to Andromeda Synthesis Story Musk but just ended up calling her Y

• Elon Musk and Grimes cycled through multiple names for their daughter, per Musk's new biography.
• Both wanted to call her Sailor Mars, after the anime character, before settling on Exa Dark Sideræl.
• But they contemplated changing her name to Andromeda Synthesis Story Musk earlier this year.

Elon Musk and Grimes considered changing their daughter's name to Andromeda Synthesis Story Musk this year, but didn't go through with it, according to the billionaire's new biography.

Musk shares three children with Grimes — elder son X Æ A-Xii, known as X; daughter Exa Dark Sideræl, known as Y; and younger son Techno Mechanicus, known as Tau.

According to the Walter Isaacson-penned biography, the couple initially considered calling their daughter Sailor Mars, after one of the heroines in the Japanese anime "Sailor Moon."

But Grimes told Isaacson they later decided to name her Exa Dark Sideræl because "she's all sparkly and a lot goofier troll."

But the couple then considered changing their daughter's name to Andromedia Synthesis Story Musk earlier this year before deciding against it. The child now goes by "Y" or "why?," per Grimes.

Musk has ten living children with three different women. Besides his Grimes' children, the billionaire has twins with Neuralink director Shivon Zilis, and five older children with his ex-wife, Justine Musk.  

Representatives for Musk and Grimes did not immediately respond to requests for comment from Insider sent outside regular business hours.