Have

Goblin Chieftain

Haste (This creature can attack and {T} as soon as it comes under your control.)
Other Goblin creatures you control get +1/+1 and have haste.

Voracious Dragon

Flying
Devour 1 (As this enters, you may sacrifice any number of creatures. This creature enters with that many +1/+1 counters on it.)
When Voracious Dragon enters, it deals damage to any target equal to twice the number of Goblins it devoured.

Goblin Chainwhirler

First strike
When Goblin Chainwhirler enters, it deals 1 damage to each opponent and each creature and planeswalker they control.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Warren Instigator

Double strike
Whenever Warren Instigator deals damage to an opponent, you may put a Goblin creature card from your hand onto the battlefield.

Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.

Mountain

Goblin Matron

When Goblin Matron enters, you may search your library for a Goblin card, reveal that card, put it into your hand, then shuffle.

Foundry Street Denizen

Whenever another red creature you control enters, Foundry Street Denizen gets +1/+0 until end of turn.

Goblin Lackey

Whenever Goblin Lackey deals damage to a player, you may put a Goblin permanent card from your hand onto the battlefield.

Tarfire

Goblin Ringleader

Haste (This creature can attack and {T} as soon as it comes under your control.)
When Goblin Ringleader enters, reveal the top four cards of your library. Put all Goblin cards revealed this way into your hand and the rest on the bottom of your library in any order.

Pashalik Mons

Whenever Pashalik Mons or another Goblin you control dies, Pashalik Mons deals 1 damage to any target.
{3}{R}, Sacrifice a Goblin: Create two 1/1 red Goblin creature tokens.

Goblin Piledriver

Protection from blue (This creature can't be blocked, targeted, dealt damage, or enchanted by anything blue.)
Whenever Goblin Piledriver attacks, it gets +2/+0 until end of turn for each other attacking Goblin.

Sword of Hearth and Home

Equipped creature gets +2/+2 and has protection from green and from white.
Whenever equipped creature deals combat damage to a player, exile up to one target creature you own, then search your library for a basic land card. Put both cards onto the battlefield under your control, then shuffle.
Equip {2}

Blood Moon

Goblin Cratermaker

{1}, Sacrifice Goblin Cratermaker: Choose one —
• Goblin Cratermaker deals 2 damage to target creature.
• Destroy target colorless nonland permanent.

Goblin War Strike

Goblin War Strike deals damage to target player or planeswalker equal to the number of Goblins you control.

Goblin Warchief

Goblin spells you cast cost {1} less to cast.
Goblins you control have haste.

Goblin King

Other Goblins get +1/+1 and have mountainwalk.

Goblin Recruiter

When Goblin Recruiter enters, search your library for any number of Goblin cards, reveal them, then shuffle and put those cards on top in any order.

Krenko's Command

Create two 1/1 red Goblin creature tokens.

Krenko, Tin Street Kingpin

Whenever Krenko, Tin Street Kingpin attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

Breath of Fury

Enchant creature you control
When enchanted creature deals combat damage to a player, sacrifice it and attach Breath of Fury to a creature you control. If you do, untap all creatures you control and after this phase, there is an additional combat phase.