What were the best debut by a Wrestler when they first appeared in the WWF/WWE. Here's mine
Tazz (Royal Rumble 2000) - prior to the first PPV of the new millennium, Raw is War episodes would show gimmicks of Tazz entrance music interrupting some matches, Tazz was not yet revealed until the Royal Rumble as Kurt Angle's mystery opponent, at Madison Square Garden, Kurt Angle was undefeated, never been pin when Tazz made a huge impact, forcing Angle to tapped out with his finishing moved. the fans chanted at the start of the first match of the evening "We want Tazz" "We Want Tazz"
Booker T (2001 King of the Ring) - In the triple-threat match for the WWE championship involving champion Steve Austin, Chris Jericho and the late Chris Benoit, Booker T, the WCW champion showed up and put WWE champion Stone Cold Steve Austin into the table, WCW was already purchased by Vince McMahon around that time when WCW wrestlers began showing their stuff in the WWE.
Diamond Dallas Page - was it Raw or Smackdown when he revealed himself as the stalker to Undertaker's wife, Sarah, Page used the Undertaker's music entrance with his face covered, he used the lines "Undertaker, make me famous."