San Francisco, May 6 (IANS): Multi-billionaire tech mogul Elon Musk has posted the first picture of his newly-born son in response to demand coming from his fans, naming the baby 'X Æ A-12 Musk'.

Musk and his girlfriend Canadian singer Claire Boucher aka Grimes welcomed their first child together on Monday.

In response to a follower's tweet asking them to name the baby, Musk said: 'X Æ A-12 Musk,' making netizens to speculate on the meaning and pronunciation of the unique name.

Grimes confirmed the name, and explained the meaning in another tweet: "X is the 'the unknown variable', Æ is her 'elven spelling of Ai", A-12 is the "precursor to SR-17".

"X, the unknown variable. Æ, my elven spelling of AI (love &/or Artificial intelligence), A-12 = precursor to SR-17 (our favourite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent + (A=Archangel, my favourite song)," she posted.

Musk posted a photo of the baby through a tattoo/eyelash filter.

"Never too young for some ink," he joked in a follow-up tweet.

The Tesla and SpaceX CEO has six children with ex-wife Justine Wilson and this ome is the first child with his new girl friend.

Grimes announced that she was pregnant on Instagram in January.

During a livestream on Twitch in February, she said that the baby's due date was May 4.

Grimes also revealed she does not want to 'gender' her baby, saying they can "decide their fate and identity' on their own accord.