When working together at Zip2, Elon Musk had to go to the ER for stitches and a tetanus shot after his brother, Kimbal, once tore off a hunk of flesh from his hand

• Kimbal Musk bit Elon Musk and "tore off a hunk of flesh" off his hand during a fight in the 1990s.
• Elon Musk had to go to the emergency room for stitches and a tetanus jab.
• The incident is detailed in Walter Isaacson's new biography.

Kimbal Musk once "tore off a hunk of flesh" from Elon Musk's hand while the brothers wrestled on the floor in Zip2's office, Walter Isaacson wrote in "Elon Musk," his new biography of the tech mogul.