Elon Musk and Grimes really followed through with their outta this world baby name ... but they had to play a little ball to comply with California law.
According to the newborn's birth certificate, obtained by TMZ, Elon and Grimes named their first child, X AE A-XII Musk. Seriously.
Mom and Dad had to get a little creative -- as if the kid's name wasn't clever enough -- to make their tyke all legal and stuff. As you know ... Elon and Grimes' baby boy was born last month, and they wanted to name him X Æ A-12 Musk.
As it turns out, the aeronautic name didn't fly in Cali, where birth names must be limited to the English alphabet -- no numbers or special signs.
The result, as you can see, is a first name X, middle name AE A-XII ... and last name Musk. See? Roman numerals ARE good for something besides Super Bowls!