Snoop Dogg and Daz Dillinger Mourn Death of Cousin Darryl 'Joe Cool' Daniel

Snoop Dogg will be bearing the Olympic torch with a heavy heart ... because he and his family are mourning the death of his cousin, artist Darryl "Joe Cool" Daniel .

The Long Beach native recently passed away -- as announced by Snoop and co. -- and he was invaluable to the rapper's career ... serving as the brainchild behind Snoop's debut album "Doggystyle" artwork.

Snoop and Daz Dillinger shared multiple tributes to Daniel on Instagram throughout the week ... and the late artist's social media is also filled with several memories with Dogg Pound members all the same.

Daniel's style of illustration is influential to this day ... Snoop enlisted him for the cover art for several projects over the years, as did other artists.

In 2015, he interviewed with his hometown Long Beach Telegraph publication and advocated for recovering drug addicts, having been one himself.

He admitted to being "high as a kite" when he drew the "Doggystyle" artwork but eventually got clean and maintained over 10 years of sobriety.

Cool was 56.

RIP