NFL's Dorial Green-Beckham -- Mug Shot ... Call Me 2 Chainz

Here it is ...the mug shot that ruined the NFL's arrest-free month in September -- courtesy of Tennessee Titans WR Dorial Green-Beckham.

DGB was popped in Missouri last Wednesday for going 65 in a 55 ... and when the cop ran his info, it was discovered the 22-year-old had an outstanding warrant for a speeding violation in another county.

He was hauled to a nearby station where Green-Beckham was booked and posed for a mug shot -- featuring 2 gold chains -- and was later released after paying his $92.48 debt.