In 1997, a storyline involving Paul Bearer telling the Undertaker that his brother Kane, who had supposedly died in a fire when the two were children, was still alive and would soon appear. During his infamous first Hell in a Cell match with Shawn Michaels, the Undertaker would be confronted by the debuting Kane, kicking off a long program between the two that would be a main attraction at WrestleMania 14.
#4. John Cena
When Kurt Angle issued an open challenge on a 2002 episode of SmackDown, little did he know that the rookie who would answer the challenge would go on to be one of the biggest draws in WWE history and the leader of the coming generation. Cena held his own both physically and verbally with Angle and the successful debut would lead in to him facing and defeating Chris Jericho at his pay-per-view debut a month later.
#3. The Nexus
The infamous Nexus invasion of Monday Night RAW is considered one of the highlights of the last few years. The rookie faction led by Wade Barrett interrupted the main event between CM Punk and John Cena and went on to destroy Cena, Punk, the referees and even the ring and ringside set itself. The incident was also infamous for the fact that Daniel Bryan was immediately fired for choking ring announcer Justin Roberts, which was considered an policy infraction in WWE’s PG environment.