John "Ecstasy" Fletcher, who co-founded the legendary hip-hop group Whodini and was known for rocking a Zorro hat like no other, has died.

John's death was announced Wednesday by Questlove, who remembers Fletcher as a "legendary and a pivotal member of one of the most legendary groups in hip-hop."

John was living in the Atlanta area, and his passing has come as a huge shock to close friends. So far, no cause of death has been announced by the family.

Together with Jalil Hutchins, John formed Whodini in Brooklyn way back in 1982 before DJ Grandmaster Dee joined in 1986 to form an iconic trio.

Whodini churned out a bunch of albums and hits, including "Freaks Come Out at Night," "Friends" and "The Haunted House of Rock."

The group earned the Hip Hop Icon Award at the 3rd Annual Black Music Honors in 2018 ... and Ice Cube's "Friday" movies often referenced Whodini songs like 'Friends' and 'Freaks.'

John, who provided the vocals with Jalil, was known for his trademark hat which helped him become one of rap's first sex symbols.

Whodini, managed by Russell Simmons during their 80s heyday, was one of the earliest acts to combine rap with rock, and they were the first to perform live with b-boy dancers. Their sound heavily influenced the launch of the New Jack Swing sound.

John's death is sending shockwaves through the music industry, with many artists posting pictures of him and sharing memories.

Cube thanked him for "showing us how to do it" and Jermaine Dupri says, "Ex you know I love you thank you for every word, every conversation, every good time."

Rapper Q-Tip remembered John as "one of the most under appreciated voices in hip hop" and LL Cool J says he's "one of the most important people in this culture to me.

Chuck D's also paying homage ... recalling the time John mentored him in the summer of 1987 and was always there to reassure him advice and tips.

Ecstasy was 56.