Den of the Bugbear

If you control two or more other lands, Den of the Bugbear enters tapped.
{T}: Add {R}.
{3}{R}: Until end of turn, Den of the Bugbear becomes a 3/2 red Goblin creature with "Whenever this creature attacks, create a 1/1 red Goblin creature token that's tapped and attacking." It's still a land.

Hobgoblin Bandit Lord

Other Goblins you control get +1/+1.
{R}, {T}: Hobgoblin Bandit Lord deals damage equal to the number of Goblins that entered the battlefield under your control this turn to any target.

Battle Squadron

Flying
Battle Squadron's power and toughness are each equal to the number of creatures you control.

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.

Battle-Rattle Shaman

At the beginning of combat on your turn, you may have target creature get +2/+0 until end of turn.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Brash Taunter

Indestructible
Whenever Brash Taunter is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: Brash Taunter fights another target creature.

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.

Krenko, Mob Boss

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

Gempalm Incinerator

Cycling {1}{R} ({1}{R}, Discard this card: Draw a card.)
When you cycle Gempalm Incinerator, you may have it deal X damage to target creature, where X is the number of Goblins on the battlefield.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Goblin Warchief

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

Goblin Rally

Create four 1/1 red Goblin creature tokens.

Foundry Street Denizen

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

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Krenko's Command

Mountain

Beetleback Chief

When Beetleback Chief enters, create two 1/1 red Goblin creature tokens.

Goblin Chainwhirler

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

Goblin Trashmaster

Other Goblins you control get +1/+1.
Sacrifice a Goblin: Destroy target artifact.