Flavor Flav -- Tax Lien Makes Him a Public Enemy

Flavor Flav's rise to reality fame is gonna cost him ... big time -- at least according to the federal government, which claims the rapper owes nearly a MILLION bucks in back taxes from 2004-2006.

According to documents filed recently by the Department of the Treasury, Flav shorted Uncle Sam on his tax returns for the years that coincided with his return to prominence via reality TV -- with " The Surreal Life," "Strange Love" and "Flavor of Love."

Flav's tax bill isn't chump change either -- he owes $52, 243.47 for 2004, $303,035.93 for 2005 and $550,971.16 for 2006 ... for a whopping total of $906,250.56. That's a lot of friend chicken!