Amanda Bynes has lashed out at the President and First Lady of the United States, Barack and Michelle Obama, calling them "ugly".The troubled former actress - who has worried friends and family with a series of bizarre antics including disturbing tweets and legal troubles - insulted Barack and Michelle Obama in a new Twitter post, where she called them "ugly".She wrote: "Barack Obama and Michelle Obama are ugly!"However, the couple are not the only high profile victims of 27-year-old Amanda's wrath, last month, in a post on the micro-blogging site, which has since been deleted, Amanda also called Zac Efron ugly.She wrote: "@ZacEfron has an ugly face (sic)."Other celebrities to face Amanda's ire include Rihanna as she claimed Chris Brown assaulted his then girlfriend in 2009 because she wasn't pretty enough.Amanda tweeted: "Chris Brown beat you because you're not pretty enough," before adding: "@Rihanna no one wants to be your lover so you call everyone and their mother that I almost named my new dog Rihanna (sic)."She also lashed out at Rihanna's ex Drake, calling him "ugly", despite previously opening up about her crush on him.Amanda said: "Drake has the ugliest smile, ugly gums uneven teeth ugly eyes," before deleting the tweet.However, she later took to her Twitter account to, add: "I won't deny calling @drake ugly," before appearing to regret her tweets.She wrote: "I'm sorry about the tweets I said about @drake I didn't mean what I said. I hope to become friends with him instead of smashing him!"