Inspired by a comment on the Penny Arcade forums (and with the help of this guide), I took a shot at creating a custom culture. Let me know what you think!

Goblins of the Misty Mountains 

Standard of living: Goblins scrape by on what meager animals they can kill in their underground caves. Their primary desire at all times is what will constitute their next meal. For this reason, their culture ranks as Poor. 

Suggested Callings: Slayer, Treasure-hunter. A Goblin cares for but two things in this world: food and shiny things. 

Unusual Calling: Scholar. Goblins despise what they call book-learnin’. 

Cultural Blessing: Bloodlust: Goblins are nothing less than killing machines. When a Goblin causes an enemy to suffer a wound, the goblin may ignore the effects of being Weary or Miserable for the remainder of combat.

Common Skills: Awe 2, Athletics 3, Awareness 1, Travel 2, Stealth 1, Explore 2, Hunting 2, Craft 1, Battle 2, Song 2, Healing 1 

Weapon Skills: Swords 2, Spear 1, Bow 1 OR Maul 2, Axe 1, Spear 1 

Maul: A hunk of spiked stone set atop a warped axe-handle. Unwieldly to most, deadly to a goblin. 
Damage: 7 Edge: Tengwar Injury: 18 Encumberance: 3

Specialties: Choose 2 from the following list: Beast-Lore, Enemy-Lore (choose one from Dwarves, Wolves, Hobbits, Men, or Elves), Fire-making, Mountaineer, Smith-craft, Tunneling. 

Languages: Goblins speak Orcish as their primary language. Some speak the common tongue of Man as a seconday language. 

Adventuring age: Goblins set out to adventure as soon as they are strong enough to hunt on their own. 

Backgrounds: 

1 - Warg Rider: You have been assigned to lead the hunt atop a snarling wolfbeast. Basic Attributes: Body 7, Heart 2, Wits 5. Favoured skill: Travel. Distinctive Features: (Choose 2) Fierce, Grim, Hardy, Keen-eyed, Reckless, Swift, Vengeful, Wrathful. 

2 - Beast Wrangler: It’s your job to drag along the trolls and giant beasts without getting stomped on. Basic Attributes: Body 6, Heart 6, Wits 2. Favoured skill: Awe. Distinctive Features:(Choose 2) Bold, Cunning, Determined, Elusive, Gruff, Hardened, Swift, Wary. 

3 - War Drummer: The drumming of a goblin is known to break the bravest of souls. Basic Attributes: Body 5, Heart 4, Wits 5. Favoured skill: Song. Distinctive Features: (Choose 2) Cunning, Eager, Energetic, Hardy, Quick of Hearing, Proud, Reckless, Robust. 

4 - Dwarfslayer: Your hail from Azog’s clain, who slew King Thror and sparked the War of Dwarves and Goblins. Basic Attributes: Body 7, Heart 4, Wits 3. Favoured skill: Athletics.Distinctive Features: (Choose 2) Adventurous, Bold, Fierce, Hardened, Lordly, Proud, Tall, Vengeful. 

5 - Surface Scout: You are of an elected patrol in charge of seeing the world above. Basic Attributes: Body 5, Heart 6, Wits 3. Favoured skill: Explore. Distinctive Features: (Choose 2) Adventurous, Cunning, Elusive, Hardy, Keen-eyed, Quick of Hearing, Swift, Wary. 

6 - Battle Chef: Catch the meat, cook the meat. Basic Attributes: Body 7, Heart 5, Wits 2. Favoured skill: Hunting. Distinctive Features: (Choose 2) Clever, Curious, Energetic, Generous, Merry, Robust, Secretive, Suspicious.

Virtues

Warg – You have forced a vicious, snarling Warg into service to help you hunt and slay enemies of the Great Goblin.

In general, treat this ability as a Woodman’s Hound of Mirkwood (Adventurer’s Book, p. 133), except where noted below:

• You gain no hope from training a Warg. You are not friends; this is not the story of a boy and his dog.
• A Warg is a fighting beast first and foremost. Instead of the Support ability, your Warg begins with the Harass Enemies ability. It may learn other abilities as a Hound of Mirkwood.
• When training your Warg in the Support ability, you may add the Battle skill as an available option.

Massive in Size – A lifetime of violent combat has led you to become massive, bloated with fat sacs and muscle. When fighting foes smaller than you, your basic Parry rating is calculated using your favoured Body score, instead of your basic Wits.

Outside of combat, you gain the “Tall” trait, and may invoke it normally.

Strength in Numbers – Goblins are tribal things, used to fighting in chaotic swarms. When you and at least one other character* are engaged in hand-to-hand combat against the same opponent, add a bonus of +3, or your Valour rating (whichever is higher), to the total Endurance loss inflicted by each of your blows.

* The Warg Virtue does not trigger this benefit.

Minion of the Shadow – Over the years, Goblins’ dangerous relationship with the Shadow has provided them a keen sense of martial prowess… at a deadly cost.

At the start of combat, you may spend a point of Hope add your current Shadow score to all offensive and defensive rolls made for the duration of combat.

Iron Stomach – Years of eating whatever you found in dank, cold caves have left you with a superhuman constitution. When travelling, you may spend a point of Hope to reduce the difficulty of your Fatigue checks by your favoured Body rating.

Rewards

Uruk-Hai blade (Long Sword) – the blades crafted by Saruman’s High Orcs are massive, haphazardly-designed artifacts, covered in spikes and unwieldy ridges. They provide little additional benefit in combat—indeed, their spikes also get stuck in opponents, slowing down their wielder—but their image provides a terrifying visage that helps route opponents from afar. When using your Awe skill to intimidate foes in combat, you may roll twice, and take the better result.

Horned Helm (Helm) – Crafted with long, jagged lengths of stone on all sides, this massive helmet provides yet another way to rip into your opponents’ flesh in a moment’s notice. When making a melee attack against an opponent, you may add your helm’s encumbrance to your damage rating.

Heavy Crossbow (Great War) – Crafted by expert engineers, this crossbow tears through opponents with reckless disregard. When you roll a Tengwar rune while making a ranged attack, add +4 to your injury rating.