In the spring of 1997, Super Crazy, as Histeria, made a couple of appearances for the World Wrestling Federation (WWF). Histeria worked mainly against Venum in his appearances on Raw is War and Shotgun. In November 1997, he changed his name to Super Loco, mainly competing on their Super Astros show. His only "main show" appearance was a loss to El Águila in the first round of the WWF Light Heavyweight Championship tournament.
Super Crazy was signed to a contract by Extreme Championship Wrestling (ECW) in 1998. Crazy defeated Antifaz del Norte in his televised ECW debut on the December 31 episode of Hardcore TV. He was brought in to showcase cruiserweight action and was paired with other smaller wrestlers in a series of matches for the next two years.
His first major rivalry in the cruiserweight division came against Yoshihiro Tajiri, as the duo competed against each other in a series of matches in the first half of 1999, where the duo exchanged wins on Hardcore TV, supercards, and the Guilty as Charged and the Living Dangerously pay-per-view events. Crazy followed with participation in a series of matches with international cruiserweights as he racked up wins against fellow luchador Mosco de la Merced at CyberSlam, Japanese wrestler Taka Michinoku at Hardcore Heaven, while losing to Little Guido at Hostile City Showdown and defeating him at July's Heat Wave pay-per-view.
Crazy closed the year with two high-profile three-way dance matches, the first against Tajiri and Guido at Anarchy Rulz, and the second against Tajiri and Jerry Lynn at November to Remember. In the end of the year, Crazy joined forces with rival Tajiri and defeated Jerry Lynn and Little Guido in a tag team match at Guilty as Charged on January 9, 2000.
Super Crazy was booked to win a tournament in March for the World Television Championship after the title had been vacated by Rob Van Dam due to an injury. He defeated CW Anderson in the quarter-final round on March 4, Little Guido in the semi-final round and Rhino in the final round at the Living Dangerously pay-per-view, despite interference from The Network. Crazy made his first televised title defense against Rhino on the March 31 episode of ECW on TNN. He dropped the title to Yoshihiro Tajiri in a three-way dance, also involving Little Guido on the April 14 episode of ECW on TNN. After the title loss, Crazy faced Guido and Kid Kash in a three-way dance at CyberSlam, which Guido won.
Super Crazy went on a hiatus for the next few months until pre-taped vignettes began airing on television in October, which hyped his return at the November to Remember pay-per-view. He was initially booked to face CW Anderson at the event, but he was replaced by Kid Kash. Later in the night, he participated in a match for the ECW World Tag Team Championship between The Unholy Alliance (Yoshihiro Tajiri and Mikey Whipwreck) and Full Blooded Italians (Little Guido and Tony Mamaluke). Crazy substituted for Whipwreck after the latter got injured, but FBI retained the titles. Crazy teamed with the Unholy Alliance against Hot Commodity (EZ Money, Julio Dinero and Chris Hamrick) in a six-man tag team match on the November 19 episode of Hardcore TV. Crazy's team lost and the Unholy Alliance turned on him when Whipwreck helped Tajiri in defeating Crazy in a match. Crazy brought Kid Kash as his mystery partner against Unholy Alliance in a tag team match at Massacre on 34th Street on December 3, which Crazy's team lost. Crazy and Kash were pitted against the Unholy Alliance and Full Blooded Italians in a three-way dance at ECW's final pay-per-view Guilty as Charged on January 7, 2001; The Unholy Alliance won the match. Crazy performed at ECW's final show on January 13, where he lost to Tajiri. ECW folded down as it was bought by WWF due to bankruptcy.
In 2005, Crazy signed a contract with World Wrestling Entertainment (WWE). He initially appeared at the WWE-promoted ECW One Night Stand on June 12, 2005, winning an international three-way dance by pinning Yoshihiro Tajiri in the final pinfall of the match. During the match, he performed a moonsault from a second story balcony.
Crazy's first appearance on WWE television came during the June 18, 2005 airing of SmackDown!'s sister show WWE Velocity, teaming with Psicosis to defeat Akio and Billy Kidman. Psicosis, Super Crazy, and Juventud grouped together to form a stable known as The Mexicools. The group made their debut as heels on the June 23 edition of SmackDown!, when all three members rode to the ring on John Deere lawn mowers with the decals altered to say Juan Deere and wearing matching coveralls. They then attacked Chavo Guerrero and Paul London during their Cruiserweight Championship match. Juventud cut a promo questioning the lack of "true Mexican luchadores" in the Cruiserweight Division, before going on to deride the current state of Mexican Americans in general. Psicosis dubbed the lawnmower they arrived on a "Mexican Limo 2005". In the following weeks, they continued to interfere in matches and mock the stereotypical image of Mexicans in the United States.
Despite being introduced as heels, the group quickly became favorites of the audience and eventually began acting as faces. They received strong approval from the audience even during their debut, which occurred in Tucson, Arizona. The Mexicools' pay-per-view debut was on July 24 at The Great American Bash, defeating the bWo in a six-man tag team match. During the December 2 SmackDown!, Super Crazy and Psicosis competed in an over the top rope battle royal against five other tag teams. The pair managed to win and earned themselves a match against MNM at Armageddon for the WWE Tag Team Championship. Unfortunately for the Mexicools, MNM lost the tag team titles before their match. Not long after, Super Crazy and Psicosis became the only Mexicools left in WWE, as Juventud was released from WWE on January 6, 2006. Super Crazy and Psicosis continued to wrestle as a tag team, but Crazy got his own push as a singles competitor, eventually earning himself number one contendership for the WWE Cruiserweight Championship. By June 2006, Super Crazy's partnership with Psicosis on SmackDown! began to crumble when Psicosis repeatedly abandoned Crazy during incidents with monster heel The Great Khali. This resulted in the pairing splitting up and then engaging in a short-lived feud after Psicosis turned heel. After the breakup, both Psicosis and Super Crazy disappeared off WWE programming.
On September 4, Super Crazy had his Raw debut match and defeated Chris Masters by using his trademark moonsault. Crazy continued his feud with Masters throughout September, defeating him once more and competing with Masters, along with four other wrestlers (Johnny Nitro, Carlito, Jeff Hardy and Randy Orton) in a six-pack challenge match for the WWE Intercontinental Championship on the September 18 edition of Raw, which neither Masters or Crazy were able to win. Crazy was then involved in angles with Nitro and Melina, during which he was aligned with Mickie James, who was feuding with Melina at the time.
Super Crazy suffered an injury to his left knee at a house show which occurred on April 21, 2007 in Oberhausen, Germany. The injury was believed to be a MCL tear. Super Crazy returned to action on June 1 in a match taped for Heat, losing to the returning William Regal. On the July 2 episode of Raw, Super Crazy was Mr. Kennedy's opponent in a Beat the Clock match. Before the match began, Super Crazy appeared to have agreed to let Kennedy win, however, he defeated Kennedy with a roll-up shortly after the match began, while Kennedy was performing his introduction. Kennedy assaulted Super Crazy later that night. Kennedy then defeated Super Crazy in a grudge match two weeks later. In October 2007, Super Crazy formed a tag team with Jim Duggan. The team primarily competed on Heat to moderate success until Super Crazy was drafted to the ECW brand.
As part of the 2008 WWE Supplemental Draft, Super Crazy was drafted to the ECW brand. Super Crazy returned to SmackDown (although wearing an ECW shirt), losing to The Brian Kendrick. On the August 19 episode of ECW on Sci-Fi, Super Crazy debuted on the ECW brand, teaming with Evan Bourne and Tommy Dreamer against John Morrison, Chavo Guerrero and The Miz in a losing effort. On the September 5 episode of SmackDown!, he defeated Ryan Braddock, but was kicked by Vladimir Kozlov after the match. On the October 17 episode of SmackDown!, he lost to The Brian Kendrick's bodyguard, Ezekiel Jackson. Super Crazy's last WWE match took place the following week on the October 24 episode of SmackDown, losing against The Brian Kendrick. On November 5, 2008, WWE announced that Super Crazy was released from his contract.