Vince McMahon revealing himself as the higher power of a group that kidnapped his own daughter and probably intended to rape her if Vince's enemy Stone Cold hadn't saved her.
Bossman crashes the funeral of The Big Show's father and hijacks the casket.
Bossman tricks Al Snow into eating his dog, Pepper.
The Undertaker hangs Bossman from the Hell in a Cell at Wrestlemania XV.
Brawl for All - A legit shootfighting tournament which shorted the careers of "Dr. Death" Steve Williams and Savio Vega. Steve Blackman and Road Warrior Animal suffered injuries as well and were put on the injured list.
Bart Gunn ends up winning the tournament and goes on to get knocked out by Butterbean in 30 seconds at Wrestlemania XV.
Road Warrior Hawk's real life substance abuse problems are brought to light as we see him getting depressed and climbing to the top of the Titantron. Droz climbs up, apparently to help him, only to throw him off. It is later explained that Droz was enabling Hawk's addictions so that he could take his place in the Legion of Doom.
The Intercontinental Champion, Jeff Jarrett, becomes a sexist asshole and ends up in a feud with Chyna. He ends up jobbing to Chyna, resulting in the first female Intercontinental Champion.
Rikishi runs over Stone Cold and eventually turns heel once he is outed as the perpetrator. He explains that he "Did it for... Da Rock". Naturally he couldn't be taken seriously as a heel because he was a fat Samoan man in a thong.
Mae Young takes her top off at Royal Rumble 2000 and briefly got past the censors. It was later revealed that she wore prosthetic breasts.
Beaver Cleavage - Headbanger Mosh begins appearing in vignettes mocking 1950s sitcoms in which he insinuates that he wants to drink his mother's breast milk.
Chaz - The Beaver Cleavage gimmick is dropped via a worked shoot and Chaz is born. Mrs. Cleavage (Portrayed by the late Marianna Komlos) is revealed to actually be his girlfriend. Komlos alleges that she is a victim of domestic abuse at the hands of Chaz.
Hervina - Harvey Whippleman in drag. Whippleman becomes the first (and only) man to win this Women's Championship with this gimmick.
Oklahoma - Ed Ferrara's infamous WCW gimmick mocking Jim Ross (right down to the Bell's Palsy condition) actually premiered on Sunday Night Heat. 
Naked Mideon - Mideon begins streaking through arenas wearing nothing but a fanny pack.
Prince Albert - Better known as A-Train, Albert, or Giant Bernard; named after a genital piercing and debuted in The Pierced Pals faction with Keys and Droz.
Keys - Better known as Vic Grimes; a drug dealer gimmick.
Droz - Called "Puke" because Vince McMahon got him to puke on command; he exploits Road Warrior Hawk's substance abuse problems to get into the LOD.
Ryan Shamrock - Ken Shamrock's kayfabe sister. She sleeps with Val Venis and later gets sacrificed by The Undertaker.
The Blue Blazer - Owen Hart's old superhero gimmick. Hart was given the gimmick again because he declined to take part in a love triangle storyline. Owen died after The Blue Blazer's superhero entrance failed at Over the Edge 1999.
Bombastic Bob and Bodacious Bart - Better known as Bob Holly and Bart Gunn; WWE's idea of The Midnight Express; Took part in the failed NWA Invasion in 1998.
Gerald Brisco and Pat Patterson - Two accomplished legends in the wrestling business become stooges to Vince McMahon.
Chainsaw Charlie - Terry Funk wears pantyhose over his face and brings a chainsaw to the ring.
Los Boricuas - A stable of Puerto Rican wrestlers.
Barbara Bush (BB) - an EMT gimmick. She got her shirt ripped off, got put through a table, and was never seen again.
The Flying Nuns - The Headbangers first gimmick; Two guys dressed up as nuns. Although they eventually dropped the habits they would keep the skirts.
Heel JR (Version 2) - JR suffers another Bell's Palsy attack. When he finally returns to RAW everybody acts like he isn't supposed to be there. Not having learned from the last time, they turn him heel again. He gets his own announcer's table and Steve Williams becomes his bodyguard. Instead of booing him he gets cheered no matter what he does.
PMS / Meat - Shawn Stasiak becomes a sex slave to Terri, Jacqueline, and Ryan Shamrock.
Bobcat - Godfather's Ho; won the Hardcore Championship.
Nicole Bass - An enormous female body builder who got it on with Val Venis. She left the company after allegedly getting molested by the Brooklyn Brawler.
LOD 2000 - The Road Warriors are repacked after jobbing to the New Age Outlaws. Oh, and Sunny managed them. This is where Puke becomes associated with the group as well.