Copy of: Competitive Krenko (EDH / Commander)

Throughout Magic's history, goblins would win battles by recklessly attacking in large numbers, often involving many of them dying in stupid ways (see the flavor texts for Goblin Grenade and Goblin Bombardment). This deck is an attempt at playing the numbers game a little bit smarter. You'll notice that there are many cards that will give Krenko haste. I've designed it so that you play your haste spell on turn 3 (Goblin Warchief, Thousand-Year Elixir), so that Krenko comes out on turn 4, with haste (Krenko will often come out on turn 3, with haste). Then you can spend the next few turns building up your goblin army, but try to keep them alive! Around turn 5 or 6, you can unleash something big to win the game (Coat of Arms, Furystoke Giant, Goblin War Strike), or you can attack in large enough numbers to reduce your opponent's life to zero. But in order for that to work, you need a decently sized goblin army. Again, keep them alive.

Winning Combos (NOTE: there are plenty of ways to win without these combos)

Eldrazi Monument: Give all your goblins indestructible, and then use either Skirk Fire Marshal or Blasphemous act to destroy all creatures... except for yours. Just keep in mind that this is useless against decks that don't use creatures (Teferi, Temporal Archmage).

Thornbite Staff: Krenko now untaps when a goblin token dies... which means you get infinite goblins with any sac outlet (Goblin Sharpshooter and Goblin Assassin can also work). Use Goblin Bombardment for infinite damage, Skirk Prospector for infinite red mana, or a haste enabler for an all out attack. If for some reason attacking is not an option (Caltrops, for example), but you're generating infinite Mana (Through Skirk Prospector, Mana Echoes, or Ashnod's Altar), you can use Thornbite Staff's other ability to shoot everyone to death.

Umbral Mantle: Pair it with either Skirk Prospector, Ashnod's Altar or Mana Echoes to generate infinite goblins, and infinite mana.

Breath of Fury: You'll need an opponent who doesn't have any creatures to block with (common enough in my meta, maybe not in yours) and a global haste enabler (Goblin Chieftain, Mass Hysteria, Goblin Warchief, Fervor, or Hammer of Purphoros). Use a goblin token with Breath of Fury attached to it, and attack the player who can't block. Use all your other goblin tokens to attack the other players. After that combat, Breath of Fury snaps on to another token, and all your creatures untap. Tap Krenko to make more goblin tokens, that all have haste. Attack relentlessly to win. NOTE: the haste enabler is not necessary if you happen to have a huge number of goblins.

Here are some special cards that are worth noting:

Goblin Assassin: A pseudo board wipe. It will affect your opponents more than yourself. The only downside is actually flipping 20 coins. You might want to use a coin-flipping app.
http://www.shodor.org/interactivate/activities/Coin/

Goblin Sharpshooter: Kill something with 1 toughness, Sharpshooter untaps, repeat. Useful for getting rid of mana dorks.

Goblin Recruiter: I usually search for Goblin Warchief, Skirk Prospector, and then a third goblin that could help out in my current situation (Sharpshooter for mana dorks, Goblin Assassin for mass creature removal, Goblin Piledriver for the blue player).

Obelisk of Urd: While not as good a buff as Coat of Arms, you will usually be able to cast it for 0 mana.

Pyroblast: There are two kinds of Magic players; those that hate blue players... and blue players.

Skirk Fire Marshal: Awesome board wipe. You can also stack the triggers if you want to do 20 or 30 damage. Plus it has protection from red, so it can survive to do it again. If you can't win, you're taking everyone else with you.

Warren Instigator: This card would be really good if most goblins didn't already cost one mana. Still, playing two goblins for free helps set the board for when Krenko comes out.

Another important thing to note is that there are only a handful of cards that will let you draw more cards. Skullclamp (two cards per goblin), Wheel of Fortune, Dark-Dweller Oracle (kinda like drawing cards), and one card with cycling (Gempalm Incinerator). Lack of card draw is the downside to this deck. The upside is that you will be able to do a lot of things with a low mana curve. You'll be able to win games with only two or three mountains, but you'll need cards like Goblin Warchief, Skirk Prospector, or Goblin Lackey.