Legend has it Roberts invented the DDTcompletely by accident.
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 somewhat 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 Foleynot to tell him Mick's ideas for a scene between the two of them. All of Vince's reactions are genuine.
When André the Giant officially made his Face-Heel Turn on Piper's Pit by ripping the crucifx 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.
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.