Who knew that when Eminem dropped the lyrics Grow your beard out, just weird out in his new comeback single "Berzerk" that he was talking about famous music producer Rick Ruben? We certainly didn't until we watched his new music video for the rock-heavy hit featuring the furry-faced legend.

Who else pops up in Em's new vid? When the rapper delivers the line So come get on this kids rock, baw wit da baw, bang bang / P-p-p-pow pow chicka wow wow, who else but Kid Rock shows up? We only wish Kevin Federline made an appearance when Eminem says Make just like K-Fed and let yourself go...

Keep your eyes peeled for young rapper Kendrick Lamar and hip-hop supergroup Slaughterhouse as the Beastie-Boys-influenced video rolls out. Watch Eminem's star-studded "Berzerk" music vid on VEVO below...what are your thoughts on the clip and the lyrics?