Billionaire Elon Musk, CEO of Tesla and SpaceX, welcomed his first child with girlfriend Grimes, a Canadian singer, on Monday. The singer has explained the meaning behind her son's unconventional name, while Elon has shared a picture of the baby along with a tattoo filter.

Elon Musk and Grimes have apparently named their son 'X AE A-12.' Explaining the meaning behind the name, Grimes reportedly said, " 'X' stands for the unknown variable, 'AE' is the musician's 'elven spelling of AI (love &/or artificial intelligence),' 'A-12' is, as gathered, a reference to the Lockheed A-12, or, in Grimes' words, the 'precursor to [the] SR-17 (our favourite aircraft). No weapons, no defences, just speed. Great in battle, but non-violent. A=Archangel, my favourite song." Grimes revealed her pregnancy in early January by posting a picture exposing her baby bump, which also had the image of a foetus photoshopped on it. Elon Musk is already a father of five children, Griffin, Kai, Xavier, Saxon, and Damian, from his first marriage to author Justine Wilson, while his newest son is his first child with Grimes.

Grimes has been in a relationship with Elon Musk since May 2018 and the couple confirmed the same during their appearance at the Met Gala.