She's not having a great time of it lately, what with her arrest this week.
And it seems Amanda Bynes is taking out her anger with a random attack at Rihanna.
The 27-year-old wrote a number of offensive tweets about Ri-Ri on Twitter, before deleting them.
After deciding exactly what she wanted to say, however, she stuck with the following message: "@rihanna you look so ugly tryin to be white."
The former Disney star added: "Chris Brown beat you because you're not pretty enough."
Amanda then retweeted a post of Rihanna's and added to it: "'Look who came to see me!! My lover Stella McCartney!!!' No one wants to be your lover so you call everyone and their mother that I almost named my new dog Rihanna."
Known for her fiery temper on Twitter, Rihanna quickly responded, simply saying: "Ya see what happens when they cancel Intervention?"
But Amanda wasn't going to leave it there.
She replied: "Unlike ur fugly faced self I don't do drugs! U need the intervention dog! I met ur ugly face in person! U aren't pretty u know it!"
The girls, pictured together in 2006, have no history of bad feeling as far as we know, but reports suggest Amanda's unrequited love for Rihanna's ex-boyfriend Drake, might have something to do with it.