'Rob & Big' Star Big Black Dead at 45.
Christopher 'Big Black' Boykin, who was the other half of Rob Dyrdek's hit MTV show "Rob & Big" -- has died ... TMZ has learned.
No official cause of death yet, but multiple people connected to Chris tell us they believe it was a heart attack.
He was Rob's best friend and bodyguard on their reality show, which ran from 2006 to 2008 -- and also later appeared on 'Fantasy Factory.'.
Rob talked about their falling out a couple of years ago.
Not only did they work together on 'Fantasy Factory' ... but Chris recently posted a throwback pic of them from the show's heyday. »