While Elon Musk and Amber Heard had nothing negative to say about each other after their split in 2018, according to Elon's friends and family, Heard was a nightmare girlfriend.

In the biography titled “Elon Musk” written by Walter Isaacson, Elon's brother Kimbal Musk called Heard “toxic” while Elon's chief of staff compared her to “the Joker in Batman.”

The author detailed Elon and Heard's tumultuous fights, which included the actress locking herself in a room and claiming she was afraid of being attacked.

“She really is a very good actress so she will say things that you're like: ‘Wow, maybe she's telling you the truth,’ but she isn't,” Kimbal revealed in the biography.

Kimbal also confessed that Heard reminded him of his father, while Elon's ex-girlfriend Grimes compared her to a Dungeons & Dragons character, and called her “chaotic evil.”