
In August 1997, Shaggy and Violent J, the Insane Clown Posse, opened Extreme Championship Wrestling (ECW)'s Hardcore Heaven pay-per-view by performing songs and exciting the crowd. Then Rob Van Dam and Sabu attacked them. This led to The Sandman coming down to save them by chasing away Van Dam and Sabu with his signature Singapore cane.
In 1998, Insane Clown Posse were asked by the World Wrestling Federation (WWF) to perform the entrance theme for the wrestling group The Oddities. The WWF also wanted them to appear on their SummerSlam pay-per-view program in August 1998 and rap live while The Oddities entered the ring. Insane Clown Posse performed and were asked to return for the live broadcast of Monday Night Raw the following night.
Insane Clown Posse were then put in a feud with The Headbangers. In their first match, The Headbangers were stiff, throwing real punches and kicks. In the rematch, a move was planned where The Headbangers would be flipped over by ICP. When the time came to flip over, however, The Headbangers refused to move, forcing Insane Clown Posse to genuinely flip them over and begin throwing punches.
Soon after, the ICP suddenly turned on The Oddities in their match against The Headbangers, then joined the Headbangers in beating up the group. The next week, Insane Clown Posse and The Headbangers had a match with Steve Austin. Following the match, ICP left the WWF.
Shaggy then went on to wrestle a long stint in World Championship Wrestling in 1999 with Violent J. The duo formed two stables. The first stable, The Dead Pool, consisted of Insane Clown Posse, Vampiro, and Raven; the second consisted of Insane Clown Posse, Vampiro, Great Muta, and the Demon, known as The Dark Carnival.
On August 9, 1999, Insane Clown Posse made their WCW debut on Monday Nitro in a six-man tag team match. Insane Clown Posse and Vampiro defeated Lash LeRoux, Norman Smiley, and Prince Iaukea. At Road Wild 1999, Rey Mysterio, Jr., Billy Kidman, and Eddie Guerrero defeated Vampiro and Insane Clown Posse. Insane Clown Posse continued to wrestle on Monday Nitro, defeating Public Enemy one week, and losing to Konnan and Rey Mysterio, Jr. another. At Fall Brawl 1999, the tag team of Rey Mysterio, Eddie Guerrero, and Billy Kidman again defeated Vampiro and Insane Clown Posse. On September 13, Insane Clown Posse defeated Lenny Lane and Lodi.
On the August 23, 2000 episode of WCW Thunder, Great Muta, Vampiro, and Insane Clown Posse beat Tank Abbott and 3 Count. Five days later, on Monday Nitro, Insane Clown Posse and Vampiro defeated 3 Count, and the following week, Rey Mysterio, Jr. and Juventud Guerrera beat Insane Clown Posse. On September 25, Mike Awesome defeated Insane Clown Posse in a handicap hardcore match. The ending showed Awesome performing his signature Awesome Bomb on 2 Dope on top a bus. Shaggy was stunned and accidentally fell off the top of the bus. ICP left WCW soon thereafter.