According to recent reports,AmazonsFounder Jeff Bezos has invested in an anti-aging biotech company called Altos Labs. As soon as the news came out, it immediately attracted his old rivals,TeslaA mockery with SpaceX CEO Elon Musk.

In his consistent style, Musk responded to a tweet about Bezos' new investment and possible salaries for Altos Labs scientists.

He wrote, “If this doesn't work, even the Grim Reaper will sue!” This is apparently echoing a previous tweet in which Musk satirized Bezos' full-time job after retirement was to sue SpaceX.

The rhetoric dispute between these two top wealthy people is getting more intense. Bezos' Amazon company complained to the US Federal Communications Commission (FCC) on Wednesday, accusing SpaceX of blatantly flouting US laws and regulations. This is an act that clearly violates fair competition in the market. Amazon claims that Musk's actions are tantamount to saying that the regulations are all made for others and do not apply to him. Businesses that abide by the rules or require compliance from other companies are relentlessly ridiculed and attacked by him.