Here's an Orc deck that tries to utilize the endless loop combo of Urguck + Skarsnik and Gobbla + Lord of Change + Fists of Mork.
3 Baby Suig
3 Squig Herders
3 Squig Lobber
3 Squig Trackers
2 Great Cave Squig
3 Skarsnik and Gobbla
3 Lord of Change
3 Warpstone Excavation
3 Contested Village
3 One Orc's Scrap
3 Squig Pen
3 Mork's Teef Ritual
3 Fists of Mork
3 Rip Dere 'Eads Off!
3 Warpstone Experiments
3 Raise Dead
Previously, there was one endless loop combo in Invasion, the High Elves' Loremaster of Hoeth + Lelansi + 2 Outpost of Tiranoc + Gifts of Aenarion. This one here now has three advantages: it is much easier to actually get into play thanks to Rip and Raise Dead, it is more difficult for your opponent to deal with once it gets going, and its components are more effective in incomplete combinations if you can't get the whole engine assembled.
So the plan is to get Urguck, Skarsnik and Gobbla, and one Lord of Change into play, have at least one Fists of Mork in hand (or as the top card of your deck), and one resource. You play Fists of Mork, dealing one damage to Urguck and Skarsnik each, and chose to return Fists to the top of your deck. From there it can be played again, thanks to Lord of Change, with the damage on Urguck used to pay for it, and it then again deals one damage to Urguck and Skarsnik each. With every cycle, your opponent takes two indirect damage. After the third cycle, you remove three damage from Skarnsnik for his effect. Rinse and repeat. Even if your opponent has units with toughness or can soak up the damage from Fists in other ways, he most likely can't handle the damage to his capital from Skarsnik.
How do you get there? Standard reanimator fare. Either you get the Lord of Change into your discard pile by playing him as a development, sacrificing him to One Orc's Scrap or the Giant Cave Squig, and bring him back with Raise Dead, or you use Mork's Teef Ritual, or you just play him as a development and use Rip if you can execute the combo in that turn. For more on reanimator decks, I refer you to Vitamin T's showcase at http://www.fantasyflightgames.com/edge_news.asp?eidn=2297. Usually you shouldn't have trouble playing the two Orc heroes normally, but all of these are options for them too, especially if you don't want to risk one or two of them sitting in the open for your opponent to take out while you're still waiting for the rest of the engine parts.
I've been surprised how quickly one can get this going. Naturally, it helps greatly if your opponent hasn't faced this deck or a similar one before and doesn't realize what you're trying to hit him with (and how he can best put a spanner in the works of your engine). Even if you take your time, your opponent might be unable to stop you once the engine starts.
Dangers are that your opponent is too fast for you, and you don't have much control with this deck, since it only cares about assembling the engine. The Dark Elves in particular will give you a hard time with HP reduction and the potential to simply discard the Fists of Mork from your deck.
The nice thing is that you don't always need all the parts of the engine. You don't get the endless cycle without all of them, but the parts still have synergy, especially if you can afford taking the damage from Fists better than your opponent.
In general you don't need many resources, so emphasize the quest zone to collect your engine parts. Use Warpstone Experiments on units in your quest zone for increased card draw (and to get rid of troublesome Baby and Cave Squigs). The Baby Squigs help you with loyalty for Mork's, and they have nice synergy with the heroes, though you have to be a bit careful with their placement. The Great Cave Squig + Skarsnik is of course a nice combo too. Beyond that, the Squig cards are mostly there in hope of the Trackers speeding things up, you might very well replace them with standard rush units (Spider Riders etc.). Some fast damage that way makes it more likely that your opponent can't handle Fists damage from an incomplete engine well. You can also go for more control, with Lobber Crew, Pillage, etc. You can also try Advanced Engineering, Muck, and other cards that allow you to sift and sort through your deck. Raiding Parties can help you with loyalty for Mork's, speed things up, and give you another option for development destruction for Raise Dead. There are many more cards that can help, basically everything that isn't part of the engine can be scrutinized and replaced with something that helps you achieve your goal better or in a slightly different way.
I find trying to assemble the engine is fun, and I consider it an interesting challenge that there is a combo like this and how you deal with it. On the other hand it isn't exactly exciting to win with an endless loop engine, and it certainly sucks to lose against one. It's pretty boring, and for me not really in the spirit of the game. All in all I'd prefer for Invasion not to have these combos, but while it does we can mess around with them and see if they're actually worthwhile or if we don't have to worry about them. The High Elves' isn't worthwhile, this one stands a better chance.