LaMarcus Aldridge Gets Huge Back Tattoo Featuring Image Of Joker

LaMarcus Aldridge just got a new massive back tattoo featuring an image of the Joker ... and check it out -- it's so seriously awesome!!!

The former NBA star hit up Andres Ortega and his Onder Ink team last month to get the piece done ... and after sitting under the needle for 10 hours, most of the backside of the hooper's 6'11" frame was completely covered in ink.

On the bottom of the tattoo, Aldridge got Batman's nemesis tatted because, according to Ortega, the former San Antonio Spurs forward said there was a time in his life when nobody believed in him -- and this was his way of laughing at those detractors.

Aldridge also got images of a lion and its cub to represent the relationship he has with one of his children. The skyline of Dallas -- Aldridge's hometown -- was also added to the top of the artwork.

The 7-time NBA All-Star got his jersey No. 12 inked too ... and Ortega tells TMZ Sports he added religious imagery to honor his faith as well as family members who have passed.