DeMarcus Cousins Selling $5.4 Million California Mansion

DeMarcus Cousins is leaving Northern California in the rear view mirror for good ... putting his RIDICULOUS pad on the market ... and asking $5.4 milli for the digs.

The NBA superstar plopped down $4.7 million for the 6 bed, 8 bath Granite Bay joint back in 2013 -- right after inking a $62 million deal with the Kings.

The 13,690 square-foot estate is pretty freakin' insane -- featuring a Playboy-mansion-style grotto (R.I.P. Hef), film and workout rooms, a 10-car garage and even an outdoor pizza oven.

But the best part has to be his swanky lighted tennis court ... 'cause there's no sign of a basketball court on the entire property!