Musk has changed his Twitter bio to read "Zombie Defender" since he began advertising the $500 (£354, €402) flamethrowers. Around 7,000 have already been sold, from a stock of 20,000 to be dispatched in the spring. The company is also selling an "overpriced" fire extinguisher for $30.
Musk posted a video of himself testing the flamethrower on Instagram, saying: "Don't do this. Also, I want to be clear that a flamethrower is a super terrible idea. Definitely don't buy one. Unless you like fun."
The flamethrower's description on The Boring Company website states: "Guaranteed to liven up any party!
World's safest flamethrower!"
The billionaire tech magnate has encouraged customers to buy the flamethrowers by pointing out their indispensability in the event of a zombie apocalypse. He wrote on Twitter: "When the zombie apocalypse happens, you'll be glad you bought a flamethrower. Works against hordes of the undead or your money back!"
Making light of the end of the world, Musk later denied he was secretly creating a zombie apocalypse - although he clearly has a big enough factory to engineer the hordes. He wrote: "The rumor that I'm secretly creating a zombie apocalypse to generate demand for flamethrowers is completely false.
"You'd need millions of zombies for a so-called "apocalypse" anyway. Where would I even get a factory big enough to make so many!?"
Brits should be thankful a zombie apocalypse is (possibly) not in Musk's plans, as a recent YouGov survey found that just 11% of us have a zombie plan prepared. The polling company called Britain "woefully unprepared".
However, more young people are prepared for a zombie apocalypse - 23% of 18 to 24-year-olds know what they would do in the event of an undead outbreak, compared to just 3% of those aged 55 and over. Men are also more likely to have a contingency plan than women (14% compared to 8%).
Musk will be hoping to appeal to the 23% of those who said their plan would involve acquiring weapons, and the 13% who are prepared to kill the walking dead and even other survivors, as well as those who just want to play with fire.
The flamethrower is believed to be legal in the US, as according to Musk, the Bureau of Alcohol, Tobacco and Firearms allows a weapon with a flame shorter than 10ft. Musk clarified: "Our design is max fun for least danger. I'd be way more scared of a steak knife."
It is unclear whether the flamethrower is legal in the UK or other countries. It may even be classed as a dangerous weapon, but at least The Boring Company will let you have a refund if the flamethrower is restricted or made too costly by customs fees in your country.