Have

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Goblin Ringleader

Haste (This creature can attack and {T} as soon as it comes under your control.)
When Goblin Ringleader enters the battlefield, 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.

Goblin Instigator

When Goblin Instigator enters the battlefield, create a 1/1 red Goblin creature token.

Putrid Goblin

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Goblin Matron

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

Swamp

Skirk Prospector

Mountain

Goblin Oriflamme

Attacking creatures you control get +1/+0.

Sling-Gang Lieutenant

When Sling-Gang Lieutenant enters the battlefield, create two 1/1 red Goblin creature tokens.
Sacrifice a Goblin: Target player loses 1 life and you gain 1 life.

Munitions Expert

Flash
When Munitions Expert enters the battlefield, you may have it deal damage to target creature or planeswalker equal to the number of Goblins you control.

Rakdos Guildgate

Rakdos Guildgate enters the battlefield tapped.
{T}: Add {B} or {R}.

Goblin Warchief

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

Outnumber

Outnumber deals damage to target creature equal to the number of creatures you control.

Volley Veteran

When Volley Veteran enters the battlefield, it deals damage to target creature an opponent controls equal to the number of Goblins you control.