Legend has it Roberts invented the DDTcompletely by accident. (Of course, one can think otherwise by keeping in mind that Satoru Sayama used a similar move only a few years before.)
The infamous "snake bite" angle involving Randy Savage, where the viper was increasing its bite, was the result of Roberts being unable to get the snake to release its grip; he had to improvise to make it appear he was making the snake be more vicious than it actually was.
According to Ahmed Johnson, Goldust kissed him on the mouth for real during one of their matches, and Johnson's fury afterward was legit.
After the Shockmaster famously tripped during his debut entrance in a Flair for the Gold interview segment, they reworked the character to be a big clumsy oaf instead of a superhero type.
Shortly after the Power Stable of Ric Flair, Arn Anderson, Ole Anderson and Tully Blanchard got together Arn Anderson made the offhanded remark, "The Last Time four guys in one place did this much damage, it was The Four Horsemen of the apocalypse." The name stuck.
A famous moment when The Rock's shades fell off and Mankind simply picked them up and put them back on Rock's face was completely on accident.
Vince McMahon flat out asked Mick Foley not to tell him the ideas for a scene between the two of them. All of McMahon's reactions were genuine.
When André the Giant officially made his Face–Heel Turn on Piper's Pit by ripping the crucifix necklace off of Hulk Hogan's body, he accidentally left a scratch on his skin. The accident, along with Piper informing Hogan "You're bleeding" during the aftermath, resulted in the segment having an even bigger impact in terms of Andre being a threat to Hogan's world title.
At the beginning of the September 25, 2006 edition of Raw in Oklahoma City, the arena suffered a temporary blackout up until the end of the first set of commercials. After the power was restored, John Cena gave a promo where he claimed Edge, whom he had recently won the WWE Championship from at Unforgiven, had caused the power failure because he was still bitter about losing the title.
Before the WWE hired script writers, all interviews were improvised. While they were told what topics to cover and maybe given a couple lines to say, everything else was made up on the spot.
AJ Styles invented his finishing move, the Styles Clash, when he botched a power bomb.
Titus O'Neil once had a match with Antonio Cesaro right after O'Neil had just won an eating contest. After Cesaro used the Giant Swing on him, O'Neil stumbled out of the ring and puked. O'Neil can will himself to puke and did it because he thought it would be funny.
Jimmy Hart (former Trope Namer for Suspiciously Similar Song) got his "Mouth of the South" moniker from a DJ. Hart was filming an angle for Memphis with Andy Kaufman during a radio interview. Since Hart was functioning as Kaufman's mouthpiece, he did most of the talking. The DJ said, "Well you're just the mouth of the south, aren't you, Jimmy?" Jimmy thought it was pretty good and kept it.