Some times the best thing to do to describe a band is just qoute wikipedia:
After rising to Internet fame with their 2008 song “Combination Pizza Hut and Taco Bell”, Das Racist established themselves as rappers with the release of their 2010 mixtapes Shut Up, Dude and Sit Down, Man. Spin picked Das Racist as one of fifty acts to watch at the 2010 SXSW festival, and in April 2010, MTV Iggy selected Das Racist as one of the “25 Best New Bands in the World”. Rolling Stone declared the song “hahahaha jk?” from Sit Down, Man one of the fifty best singles of 2010.
Yes, this guys are the serious joke ever but unfortunately they ended their partnership in 2012. They left behind a lot of material though, spread across youtube and soundcloud.