YG is so happy with the way Todd Gurley and the Rams are playing this season ... dude just had to say thanks to the running back -- WITH A DOPE NEW CHAIN!!!
The superstar rapper is a huge L.A. Rams fan -- and with the team off to one of its best starts in franchise history ... YG hit up Jason Of Beverly Hills to get the squad's best player a present.
We're told YG had 4 "4 Hunnid" pendants made ... with nearly 3 carats of flawless white diamond in each -- and gifted one of them to Gurley before L.