Beta testers can be likened to a vehicle's early warning device. It tells the other vehicles behind that something is wrong up ahead, and so beware. Well, upcoming WoW expansion, the Burning Crusade, has beta testers and they have a heads up for all of us: beware the Fel Reaver.

When BC finally arrives, all players will begin anew their conquest on the Hellfire Peninsula. Now, this location is being guarded by the Fel Reavers. These are actually enormous level 70 demonic machines. Just to take one down requires a raid group, if you want to know the painful truth.

While only a few information is known about them for now, they are not exactly new creatures. The Burning Legion has been using them as sentinels around their forges to the north to oversee the work on their cannons. The development team over at Blizzard probably knows how dangerous these creatures are and so they provided players some invaluable head start. Fel Reavers move rather slow and they make the ground shake as they move.

So if your screen starts shaking and you hear something remotely related to an engine, just run. Don't look back and just run. But if you are brave enough and you have your team with you, sneaking up on one of these guys always sounds fun...