Amanda Bynes ATTACKS Rihanna Twitter: Troubled Actress Says 'Chris Brown Beat You Because You're Not Pretty Enough!' RiRi Fires Back,

Amanda Bynes' bizarre behavior just went to unimaginable levels. The former Nickelodeon star turned "mean girl" as she led a series of random disturbing bully-like tweets towards Rihanna.

Bynes called Rihanna a dog, and even mocked the domestic violence case between she and Chris Brown. "Chris Brown beat you because you're not pretty enough," Amanda tweeted to @Rihanna. "No one wants to be your lover so you call everyone and their mother."

Rihanna fired back, "Ya see what happens when they cancel Intervention?" Bynes was obviously furious after reading RiRi's clever indirect comment, so she followed up with "@rihanna 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!"

Ya see what happens when they cancel Intervention?

— Rihanna (@rihanna) May 26, 2013

Bynes and Rihanna's Twitter feud hated there, but for Bynes this not the first of her erratic social media abuse. 

She has made sexual advances towards Young Money rapper Drake and recently engaged in a tweeted argument with Jenny Mcarthy. While Amanda mentioned that she "doesn't do drugs" in her tweets to Rihanna, Bynes was arrested for a DUI April 2012, after sideswiping a police car with her BMW, most recently, just two days ago, she was arrested for criminal possession of pot, as well as reckless endangerment and Felony tampering with evidence.

Bynes had everyone buzzing about her strange tweets in 2010, when she announced her retirement from acting at the age of 24, The Huffington Post reported.  In the following months, Bynes began to tweet racy photos and professed her preference for "chocolate men."

Amanda's fans have been wondering if she is the next Lindsay Lohan, as her unpredictable manor hints towards possible mentally illness or drug abuse. Since retiring from acting at 24, Bynes, 27, is being herself in random Youtube video posts and inappropriate tweets.