Grand Alliance: Destruction
Led by that big git Megaboss Gordrakk of the Ironjawz, the Grand Alliance of Destruction is comprised of terrible beasties from all across the realms.
Aleguzzler Gargants
You spot a huge, terrifying, slobbering giant, wielding what appears to be a fairly venerable tree and about to turn you into tomato puree. What is the first thing you remember? Their fondness for drink, apparently. Named after their tendency to MUI (Murder Under the Influence), Aleguzzler Gargants spend their days getting completely wasted and then wandering into battlefields. They then wander around the mayhem, plucking out strange meats and eating it on the go (like your local kebab shop) or shoving it down their pants for safekeeping (again, like your local kebab shop). Forgeworld has the Bonegrinder Giant, which is bigger, meaner, and drunker, like your dad.
Grots
As sneaky and crafty as ever. Now even further down the green totem pole with even bigger greenskins about.
Gitmob - Every Grot faction has a thing, and the Gitmob's thing is wolves. Even apart from Wolf Chariots and Wolf Riders, the Gitmob gets the most units out of the little greens, and more of an ability to make a balanced army. Led by Shamans (who can also ride wolves), as well as Goblin (Grot?) Warbosses who can also ride wolves, they have some fun artillery pieces and the trollish Nasty Skulkers in their arsenal. Also... Snotlings, I guess. Tactics page here.
Moonclan - As before, these gents are generally still fanatical, squig-humping nutters. Have access to the Colossal Squig, when it takes a break from eating them. Tactics page here.
Scuttlings - Weird Grots with four legs. You'd think that these half-spider gits would be in with that Spiderfang lot, but nope. Get poison and web attacks. A bunch took a severely wrong turn and unfortunately ended up in Tzeentch's Silver Tower.
Spiderfang - Spider-botherers. You get a spider, and you get a spider! Everybody gets a spider! Their Big Bosses ride atop gigantic spiders, and they have access to the mighty Arachnarok Spider. Also, lots of lovely poison attacks. Tactics page here.
Ogors
Beastclaw Raiders - Ogors riding big monsters, eternally chased by an enchanted winter. Wherever they go, shrinkage occurs. Have a total of one Ogor unit that isn't mounted on something big and nasty, with everything else being additional beasties to support them. Tactics page here.
Firebellies - Has a grand total of one unit option. These gentlemen have chronic gastric distress, which manifests itself as a flamethrower from the mouth. Tactics page here.
Gutbusters - Your classic, loveable carnivores. These guys have got a healthy appetite, just watch your Grots. Hardy heavy infantry as well as ranged options in the form of fat psychopaths carrying cannons. Fun for the whole family.
Maneaters - Again, only one unit option. At least these guys have more model variety, including that sexy female Ogor that you never knew you wanted. Oh boy.
Orruks
Still green. Still mean. Still ready to Waaagh!
Greenskinz - Oh, how the Boyz have fallen. This faction is comprised of the dregs of the Orruks, mashed into the category of "Greenskins". Led by Warbosses, who are probably a bit cheesed off that they've shifted down a couple of notches on the green scale. Better kick that Grot extra hard to relieve your size envy issues when them Ironjawz lads start laughing at you and your stunty mates. On the bright side, your army is more balanced, with ranged options and the choice of having your Warboss ride a Wyvern or Warboar.
Bonesplitterz - The "savage" Orruks. Because your run-of-the-mill Orruk wants to drink tea and discuss politics, right? The Bonesplitterz are led by shamans (Wurrgog Prophets and Wardoks), who point them to big and mean monsters to kill and eat in order to consume their strength. You see, the Bonesplitterz believe that Gorkamorka's strength is squirreled away in the living shells of big monsters, meaning that they need to RIP AND TEAR! They have a bunch of options for taking out Monster units on the table, which is handy if your opponent thinks he's clever for spamming them. These guys are as naked as the day they were spawned, with only strategically-placed trophies covering their spore sacks. They have a thing for magical tattoos, which have a chance of saving their green skins from getting mulched.
Ironjawz - Remember those dead 'ard Black Orc gits from way back when? Those are the Ironjawz' basic troops. Yeah. These are the biggest and the baddest Orruks, and the "main" Destruction faction. They wear a crap-ton of armour, and generally their bigger lads seem to be the fantasy answer to Warhammer 40k's Meganobs. Also present: huge, beasty dragon things called Mawkrushas, who share the Orruk traits of headbutting things until they stop moving, and then sitting on them. With Grimgor gone, Megaboss Gordrakk has big boots to fill. Luckily, he's got some big feet, which are ready for stompin'. Not much in the way of ranged choices and you're a bit slow, though.
Troggoths
Includes the Sourbreath (stupid), Rockgut (magic resistant), and Fellwater (bulimic). All of them spew buckets at the drop of a hat and melt anyone stupid enough to stand in front of it. Have the Troll (Troggoth?) Hag as a Leader option, so that you may seduce your opponent with the delicate sway of her sausage-like tits.
Pantheon
Gorkamorka - The combined form of Gork and Mork, mirroring the true potential of the numerous Destruction races when united under a common cause/iron fist. Otherwise, when they're divided and fighting, Gork and Mork split and fight too.
Gork - Brutal but cunnin'. Will hit you hard when you're looking.
Mork - Cunnin' but brutal. Will hit you when you're not looking.
Bad Moon - The deity of those sneaky Moonclan Grots.