It is a statement regarding poopy. It refers to excrement and the human predication to refer to slang
words in the negative of their meaning. Shit is good, and to be shit in the slang world is a good thing and to be 'shiznit' or 'the shiznit' would elevate you in the heirarchy of your 'homies' or 'nizzles'. Often used in
rap videos, or by causcasian youths trying to fabricate the experience of being an african
american. Also, in slang -'Honky wiggers perpetrating like a mug' In this case, acting in this way would not be the 'shiznit'
See also - Malibu's Most Wanted; Snoop Dogg; Any white
guy in Philly, NYC, and Little Rock as see on
HBO.