The Don't Judge Me singer wore militant dress donning Arabic robes and a turban, also wearing bullets around his neck and completing his look with a long beard.
Breezy tweeted a snap of himself wearing the costume, where he posed holding a gun and stood alongside friends who were also dressed in a similar fashion.
The 23-year old accompanied the image with the caption: "Ain't nobody F**king wit my clique!!!!#ohb"
Chris was then slammed on Twitter for his choice of outfit, with his mum Joyce Hawkins jumping to his defence, tweeting: "Halloween is for fun nothing more than just fun. Get a life please."
Brown and his pals then attended RiRi's Halloween bash at Greystones Manor in West Hollywood, where the Barbadian babe wore a cannabis themed bride costume, similar to Lady GaGa's weed creation.
According to The Daily Star, the Diamonds singer even had a bouquet made of marijuana, which she teamed with a green dress and veil.
Basketball Wives star Evelyn Loazda - who dressed as Ariel from The Little Mermaid - later tweeted a pic of herself, RiRi and friend, posting: "My 2 loves Shaniece Rihanna, Team Rihanna 411 - Love u & thank u 4 a blessed night!"
In other Chris Brown news, a court has ruled that the R&B star must stay on supervised probation as a result of his 2009 attack on RiRi.
Superior Court Judge Patricia Schnegg ordered that Chris return to court on January 17, 2013 for a further progress update.
According to The AP, Breezy's lawyer Mark Geragos was heard telling his client: "I don't dance, you don't talk", when Chris attempted to speak during proceedings.
Brown was also given permission to undertake a series of world tour dates in November and December.
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