Lil Baby loudly berated cops during his arrest in Vegas for possession of an illegal weapon, and the whole thing was caught on video.
An eyewitness tells TMZ, a squadron of cops rolled into the Encore Las Vegas Monday night and came out with the rapper in handcuffs.
As Vegas Metro PD officers were patting the rapper down near a police vehicle behind the hotel, Lil Baby shouted he has a license for the gun, and implored officers to let him go.
Cops weren't having it -- and Lil Baby got more frustrated and began talking smack ... at one point taunting officers that they should check him thoroughly because he had the "gun in his nuts."
He was eventually led into the police truck and hauled off to the Clark County Detention Center. He's since been released after posting $5,000 bail.
Shortly after his arrest, law enforcement sources told TMZ LB was caught on video being passed a gun at Vegas' Encore.
Cops arrived, investigated, and arrested him for allegedly carrying a concealed firearm without a permit.
Nevada doesn’t recognize concealed-carry permits from Georgia, where Lil Baby’s from.