I'm pretty sure the WWE likes to consider the Shock Master as the worst gimmick in wrestling history, but I would definitely have to disagree. Yeah, it's a god-awful gimmick, but it's not like it lasted or anything. There's not a whole lot worse than a fat guy in a glittery stormtrooper mask...except maybe a fat guy in a glittery stormtrooper mask that we would have had to watch for months on end... So, really the gimmick was a fail, but at least it wasn't around for very long.
Oh, wait no, the WWE officially believes that David Arquette is the worst gimmick ever. I guess he's not really a gimmick, as much as a guy who just didn't belong in the ring. But, hand it to Vince Russo to not only get him involved with the product, but make him the WCW World Champion in the process. Yeah, all of the money he made went to the familes of Owen Hart (cuz they needed it?), Brian Pillman, and Droz. So that's cool, but it was "the single greatest event responsible for the fall of Nitro." -WWE Magazine
I might just have to go with Kane the Dentist on this one... Honestly, it...just...a dentist? Really? REALLY? Personally, my least favorite gimmick I've actually experienced has got to be Eugene. Yeah, alright he's Eric Bischoff's mentally challenged nephew. Yeah, he inspired millions of people (or something). Yeah, he led to the return of the Rock. But...he was a legitimate wrestler that had to pretend to be mentally challenged, and do ridiculous things that were actually extremely offensive (in my opinion) to the actual handicap community. His matches were complete comedy, but they didn't use him against jobbers, they put him in the main event and made every week about him... They made him a Tag Team Champion, they made guys who could have been successful tag team with him. The further turned William Regal into a joke (which is saying something). And they mocked several WWE Hall of Famers by having a "mentally challenged" guy botch their signatures week after week. Seriously, if I had to watch Eugene bite another guys ass and crawl around the ring one more time, I was going to flip out. When the Rock came back I marked, obviously. But when he said "Eugene, you ain't goin nowhere!" I pretty much just gave up. Really...the Rock? The greatest of the greats, finally come home, and you're going to make it about Eugene? You would think Vince Russo was behind it, honestly...