You wanna hear something really scary?

WWE is under attack from within, and not for the first time. Every so often, the proverbial winds of change strike sports-entertainment and a group of individuals rises to challenge the system, shake up the status quo and obliterate anyone who stands in its path. It’s a tale as old as the ring itself, and it’s happening once again before the very eyes of the WWE Universe.

Witness The Wyatts' debut |  Enter The Family's world

The current scourge sweeping its way through the WWE locker room comes in the three-headed guise of The Wyatt Family, who has laid waste to several of the WWE Universe’s chosen heroes — CM Punk, Daniel Bryan, Kane, Kofi Kingston and The Miz — all at the apparent behest of some unnamed “Devil.” While The Eater of Worlds and his dead-eyed acolytes continue their mysterious vendetta, WWE.com takes a look back at previous groups who upended the world of WWE.

D-Generation X

Despite the occasional joyride on a tank, these guys weren’t so much a rebel army as a band of hooligans. However, anyone who lived through The Attitude Era can’t deny that D-Generation X changed — pardon the expression — the game for an entire generation of Superstars and fans alike.

DX reunites at Raw 1,000 |  Best of The New Age Outlaws

Bolstered by a love of all things anarchic and irreverent, the only thing that Triple H and his merry men liked more than a good joke was a good fight. The group’s irascible attitude carried them both to the apex of pop culture (though the ‘90s are gone, the DX chop gesture lingers) and WWE. Not only did The King of Kings win his first WWE Title while a member of DX, but every single member of the faction — even Chyna — was crowned with championship gold at one point. Are you ready? Clearly, most people weren’t.

The Alliance

In a shocking turn of events, ECW and WCW unite to become the Alliance.

When Shane McMahon purchased WCW, it was only a matter of time before Ted Turner’s “Big Boys” came a-callin’. And when Mr. McMahon’s old enemies finally did come to his doorstep, the Monday Night Wars finally reached the explosive apex they’d been building to for years.

Watch: Kurt Angle soaks The Alliance

The WCW holdovers were soon joined by ECW antiheroes like Tommy Dreamer and The Dudley Boyz — bankrolled by Stephanie McMahon. The two heirs promptly went to the mat against The Chairman, wreaking havoc on the WWE roster and even convincing “Stone Cold” Steve Austin to defect in the process. The Alliance was eventually disbanded after falling to Team WWE at Survivor Series 2001, but its specter has long lived on.

The New World Order

One of the most controversial and influential factions in wrestling history debuts in WWE when Hollywood Hogan, Kevin Nash and Scott Hall bring The nWo to No Way Out 2002.

The unstoppable trio of Hollywood Hogan, Scott Hall & Kevin Nash made its biggest mark in WCW, but their second run in WWE came a little too close to fulfilling its promised function as a “lethal dose of poison.”

Playlist:  The nWo in WCW

Brought in by Mr. McMahon to destroy WWE from within after control of the company began to slip from his grasp — if he couldn’t have it, no one could — Hogan, Hall & Nash not only picked up their rebellion right where it left off, but they even rallied a few more Superstars (HBK!) to their cause while administering random attacks on unsuspecting Superstars. The first to break from the nWo’s ranks was, ironically, its defining member, Hogan, and the rest of the dominoes fell almost instantly. It’s scary to think, though, that if not for a change of heart on The Hulkster’s part, the black and white might still rule the roost in WWE.

The Nexus

Raw: Wade Barrett officially welcomes John Cena to The Nexus

WWE NXT was devised as a way to groom would-be Superstars for the big stage in a way the WWE Universe had never seen before. What it ended up doing was creating a pair of truly fearsome factions that very nearly tore the McMahon empire to the studs.

The first of these two was The Nexus, a battalion of NXT Rookies who preached strength in numbers and marched, unwaveringly, to the beat of their leader, the Superstar who eventually became "Bad News" Barrett. The group wasn’t so much concerned with championship gold — though they did snag a few Tag Team Championships and Barrett was an immediate contender for the WWE Title — as changing the WWE norm. Its members nearly succeeded too, though the resilience of John Cena eventually thwarted their mission.

Watch:  The Nexus' brutal debut in full

The group had a brief, terrifying resurgence under the command of CM Punk after Barrett was ousted as their leader. Yet, a combination of Randy Orton’s punt (which took out two of its members) and The Straight Edge Superstar’s pursuit of the WWE Title eventually caused it to peter out entirely. Of course, as the WWE Universe now knows, that was hardly the last time that NXT alumni would cause trouble on the main roster …

The Shield

The Shield takes over WWE Active.

In the history of WWE, few groups have had the kind of immediate, sustained impact that The Shield has. These three graduates of WWE NXT — Dean Ambrose, Seth Rollins & Roman Reigns — didn’t want to create the kind of mayhem The Nexus thrived on. They actually wanted to bring about capital-C Change by correcting perceived “injustice” through ruthless brutality.

Watch: The Shield's monstrous Triple Powerbombs |  The Hounds strike The Undertaker

The trio made its debut at Survivor Series 2012 by Triple Powerbombing Ryback through a table and didn’t let up from there. They ran roughshod through the roster, racking up title wins (Ambrose is the reigning U.S. Champion; Rollins & Reigns boast the fifth-longest WWE Tag Team Title run in history) and honing their skills to such a degree that, even a year later, a loss by any of them is something of an anomaly. The scary part is, they’re still rolling along. The popular saying is to “Believe in The Shield.” At this point, it’s hard to imagine anyone who doesn’t.

The Corporation

When “Stone Cold” Steve Austin waged his one-man war against Mr. McMahon in the 1990s, The Chairman did the only sensible thing and assembled himself an army to fight back. McMahon used his deep pockets and persuasive nature to corral an otherwise random hodgepodge of Superstars — The Rock, Kane, Triple H, Big Show, Ken Shamrock and The Big Boss Man were all on his payroll at one point — into one of the most intimidating forces WWE has ever seen.

Acting on McMahon’s orders, The Corporation used all its powers — both physical and political — to enforce The Chairman’s agenda against the likes of “Stone Cold” Steve Austin and DX. And, by all accounts, their efforts were a resounding success. The Chairman’s men doggedly fought tooth and nail to protect his interests in keeping the WWE Title strictly in McMahon’s camp. Even so, The Corporation didn’t reach its true potential until they made a deal with The Lord of Darkness.

The Ministry of Darkness

It seems unlikely these days, but there was a time when The Undertaker walked on the dark side and all of WWE trembled before him. Christening himself as The Lord of Darkness and assembling a “Ministry” to carry out his bidding, The Deadman attempted to send WWE to hell through a mix of arcane mysticism and in-ring dominance. The Phenom’s recruits were almost as scattershot as The Corporation’s — Mideon, Viscera and The Acolytes — but their impact was just as powerful, right down to the thwarted “Black Wedding” that nearly tied Undertaker to Stephanie McMahon in unholy matrimony.

Watch:  The Best (?) of The Ministry

As it turned out, The Undertaker’s path to ultimate power was far simpler and twice as effective. Secret machinations between The Phenom and The Chairman himself led to Mr. McMahon emerging as The Ministry’s “Greater Power” and the fusing of their two factions into The Corporate Ministry.

So remember, WWE Universe, as bad as The Wyatt Family is right now, it won’t be really bad until you see Triple H in a rocking chair and fedora. Then, as Bray himself likes to say, it’s time to “run.”