Mauhúr, Uruk-hai Captain

Menace
If one or more +1/+1 counters would be put on an Army, Goblin, or Orc you control, that many plus one +1/+1 counters are put on it instead.

General Kreat, the Boltbringer

Whenever one or more Goblins you control attack, create a 1/1 red Goblin creature token that's tapped and attacking.
Whenever another creature you control enters, General Kreat deals 1 damage to each opponent.

Uglúk of the White Hand

Whenever another creature you control dies, put a +1/+1 counter on Uglúk. If that creature was a Goblin or Orc, put two +1/+1 counters on Uglúk instead.

Frogtosser Banneret

Haste
Goblin spells and Rogue spells you cast cost {1} less to cast.

Gorbag of Minas Morgul

Whenever a Goblin or Orc you control deals combat damage to a player, you may sacrifice it. When you do, choose one —
• Draw a card.
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Dawn-Blessed Pennant

As this artifact enters, choose Elemental, Elf, Faerie, Giant, Goblin, Kithkin, Merfolk, or Treefolk.
Whenever a permanent you control of the chosen type enters, you gain 1 life.
{2}, {T}, Sacrifice this artifact: Return target card of the chosen type from your graveyard to your hand.

Eclipsed Realms

As this land enters, choose Elemental, Elf, Faerie, Giant, Goblin, Kithkin, Merfolk, or Treefolk.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a spell of the chosen type or activate an ability of a source of the chosen type.

Orcish Siegemaster

Trample
Other Orcs and Goblins you control have trample.
Whenever this creature attacks, it gets +X/+0 until end of turn, where X is the greatest power among creatures you control.

Eclipsed Boggart

When this creature enters, look at the top four cards of your library. You may reveal a Goblin, Swamp, or Mountain card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Champion of the Weird

As an additional cost to cast this spell, behold a Goblin and exile it. (Exile a Goblin you control or a Goblin card from your hand.)
Pay 1 life, Blight 2: Target opponent blights 2. Activate only as a sorcery.
When this creature leaves the battlefield, return the exiled card to its owner's hand.

Boggart Mischief

When this enchantment enters, you may blight 1. If you do, create two 1/1 black and red Goblin creature tokens. (To blight 1, put a -1/-1 counter on a creature you control.)
Whenever a Goblin creature you control dies, each opponent loses 1 life and you gain 1 life.