1. Sid Vicious vs Arn Anderson
https://www.youtube.com/watch?v=4A3dBVvCcLA In October of 1993, Sid Vicious and Arn Anderson got into a confrontation at a hotel bar in Lancashire. Though words were exchange, no blows were thrown, and most of the WCW roster went to bed believing that the issue was settled. Later that night, though, Sid came to Arn's room with a weapon and attacked him when "The Enforcer" opened the door. During the brawl, Anderson grabbed a pair of scissors, and it led to a bloodbath - he was stabbed twenty times, and Sid was stabbed four times.
Recently, more light was shed on the incident when Vader guested on Steve Austin's podcast. Apparently, Austin and Vader were the last two wrestlers up at the bar, and a bleeding Sid staggered over to them in a zombie-like daze. Vader noticed that Sid was spurting blood from a hole in his abdomen, so "The Mastodon" shoved his own thumb in the wound to stem the bleeding. It was an hour before the ambulance showed up, so Vader likely saved Sid's life. He couldn't save his job, though - Sid, who was scheduled to main event StarrCade with Vader - was fired from WCW as a result of the fight.