Elon Musk Claps Back at Billie Eilish After She Slams Him for Hoarding Wealth

Elon Musk and Billie Eilish are officially at war -- at least online -- after the billionaire clapped back at the singer on the heels of her calling him a "f***ing pathetic p***y b**** coward."

ICYMI ... last Thursday, Billie went on a tirade against the tech mogul on her IG Story -- listing a slew of global issues Elon could single-handedly tackle after a new Tesla pay package put him on track to become the world's first trillionaire.

Billie argued Elon could end world hunger, save critically endangered species or even rebuild all of Gaza with his fortune ... but instead, accused him of hoarding his wealth.

Fast-forward to Wednesday night ... Elon took to his own platform, X, to hit back -- reacting to a screenshot of Billie's IG story with, "She’s not the sharpest tool in the shed."

As you know ... Billie has been outspoken against billionaires. Just last month, during her acceptance speech at the WSJ. Innovator Awards -- with ultra-wealthy folks in the room including Mark Zuckerberg -- she boldly called out the rich, saying, "I love you all but there's a few people in here that have a lot more money than me ... and if you're a billionaire, why are you a billionaire?"

Her criticism came shortly after announcing she's donating $11.5 million from her "Hit Me Hard and Soft" tour to support food equity, climate justice, carbon reduction, and the fight against the climate crisis.