All three of the original Brood members debuted in the World Wrestling Federation (WWF) in 1998. Edge made his debut in the WWF on the June 22 episode of Raw is War as a loner who entered the ring through the crowd. Gangrel made his WWF debut on the August 16 episode of Sunday Night Heat. Christian debuted on September 27 at In Your House: Breakdown, where he distracted Edge, who subsequently lost his match to Owen Hart. The storyline introduced Christian as Edge's brother.
Christian continued at the side of Gangrel to help him in his feud with Edge, and he won the WWF Light Heavyweight Championship in his first match in the WWF. Eventually, the duo convinced Edge to join them, forming the stable known as The Brood. On the October 26 episode of Raw, during a match between Kane and Gangrel, it ended when Edge ran in and attacked Kane and called Christian and Gangrel together. In their first match as a group they defeated The Oddities on the November 1 episode of Heat. On the November 2 edition of Raw, The Brood faced D-Generation X (The New Age Outlaws and X-Pac) which ended in a no contest. On the November 9 episode of Raw, Edge lost to Kane by disqualification when Kane attempted to set The Brood on fire. At Rock Bottom: In Your House, The Brood defeated The J.O.B. Squad (Al Snow, Scorpio, and Bob Holly) in a six-man tag team match.
They often entered arenas by rising through a ring of fire onto the (elevated) stage floor, with Gangrel carrying a chalice of "blood". Usually, Gangrel took a drink from the chalice (and sometimes he would pass it to Edge or Christian to drink from) and then spit it towards the crowd. One of the group's trademarks was giving their opponents a "blood bath", before or after a wrestling match. A "blood bath" consisted of the lights in the arena turning off, the flashing red lights of Gangrel's entrance coming on, and then the arena lights turning on again to reveal the target bathed in "blood". The trio had similar looking long blond hair. Gangrel and Christian both wore white shirts and dark pants, while Edge wore the long leather coat he wore before joining The Brood.
In February 1999, The Brood feuded with The Undertaker's Ministry of Darkness stable. The end of the feud saw The Brood merge with The Ministry. In March, after Undertaker's Hell in a Cell match with The Big Boss Man at WrestleMania XV, Edge, Christian, and Gangrel were lowered onto the cage from the ceiling. They lowered a noose into the cell, and the Undertaker proceeded to hang The Big Boss Man from the top of the cage. The Brood were often victims of beatings at the hands of the Ministry to both prove their loyalty to the Undertaker and to punish them. On one occasion, Christian was sentenced to a flogging at the hands of his fellow Brood members, and from the Undertaker himself after he was forced to reveal to Ken Shamrock the location of Stephanie McMahon when Shamrock held Christian in an ankle lock. When it came to the point Undertaker tried to force the Brood to sacrifice Christian alongside Shamrock, Edge and Gangrel refused, as they were more loyal to Christian than the Ministry. Instead attacking the Acolytes, the Brood split from the Undertaker's loyalty. This led to a feud with the Ministry of Darkness, specifically The Acolytes at Backlash: In Your House, The Acolytes and Viscera defeated The Brood in a six-man tag team match. On the April 26 episode of Raw, The Brood (Gangrel and Edge) lost to Kane and X-Pac, and afterwards Kane received a bloodbath. On the May 17 episode of Raw, The Brood took on The Hardy Boyz and Michael Hayes with all battling outside of the ring and the match was thrown out. On the May 24 episode of Raw, The Brood (Edge and Gangrel) lost a WWF Tag Team Championship match to Kane and X-Pac. On the June 13 episode of Sunday Night Heat, The Brood defeated The Hardy Boyz and Michael Hayes in a six-man tag team elimination match. On the July 11 episode of Heat, The Brood lost to The Corporate Ministry (Big Boss Man, Mideon and Viscera) when Gangrel turned on Edge.
By June 1999, The Brood began feuding with The Hardy Boyz. By that time, Edge and Christian had found success as a tag team. On the July 11, 1999 episode of Sunday Night Heat, Gangrel turned on Edge during a bout against The Corporate Ministry. Gangrel subsequently tried to convince Christian to do the same, but Edge and Christian instead split from Gangrel, who aligned himself instead with their rivals, The Hardy Boyz.