If you've never heard of "the word challenge," allow freestyle master King Los to introduce you. Basically, the gist is that you get people to throw random words at you, and use those as jumping off points for bars. Usually, you just keep going until you falter, then take another word, but if you're King Los, it's a nonstop onslaught for 17 minutes. Watch a particularly enthralling example of the word challenge above, filmed while Los was in Da Internz's studio.
Starting with the word "ambiguous," Los moves on to "Nestle," "homo sapien," and a whole host of others. This guy's a beast.