Another reason to never piss off Lady Gaga...

The singer went off on a former personal assistant who is suing her for almost $400,000 in unpaid overtime wages.

The New York Post reports that during a sworn deposition, the singer called her former assistant Jennifer O'Neill, a “f**king hood rat who is suing me for money that she didn’t earn."

The Post also reports that during her six-hour testimony, Gaga ranted that O'Neill thinks she's "just like the queen of the universe," and said, "she didn’t want to be a slave to one, because in my work and what I do, I’m the queen of the universe every day.”

Oooo-kay...

O'Neill filed the suit against Gaga in December 2011, claiming that she was paid $70,000 a year to be at the singer's beck and call 24-7, including, according to court papers, "ensuring the promptness of a towel following a shower and serving as a personal alarm clock to keep [Gaga] on schedule." O'Neill is claiming Gaga owes her for 7,168 hours of overtime, and Gaga is none too thrilled about it.

“This whole case is bulls**t, and you know it," Gaga told O'Neill during the Aug. 6 deposition, claiming that O'Neill enjoyed a luxurious lifestyle while working for her, saying that "she slept in Egyptian cotton sheets every night, in five-star hotels, on private planes, eating caviar, partying with Terry Richardson all night, wearing my clothes, asking YSL to send her free shoes without my permission, using my YSL discount without my permission."

Is Gaga down-to-earth or what?