Bryan Johnson (left) and Elon Musk (right).
Bryan Johnson (left) and Elon Musk (right).
  • Both Bryan Johnson and Elon Musk want to change the world. 
  • But Johnson isn't a fan of Musk. 
  • The biotech entrepreneur slammed Musk after the latter mocked his antiaging routine. 

Bryan Johnson may have expansive ambitions like Elon Musk, but the biotech CEO isn't a fan of the mercurial billionaire.

"The difference between Elon and me: I'll nourish you and drink your blood; he'll fire you and leave you to die," Johnson wrote on X on Sunday.

Johnson appeared to be referencing the mass layoffs at Twitter after Musk took over the platform.