Have

Goblin Balloon Brigade

{R}: This creature gains flying until end of turn.

Goblin Rabblemaster

Other Goblin creatures you control attack each combat if able.
At the beginning of combat on your turn, create a 1/1 red Goblin creature token with haste.
Whenever this creature attacks, it gets +1/+0 until end of turn for each other attacking Goblin.

Goblin Trashmaster

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

Shattering Spree

Replicate {R} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Destroy target artifact.

Goblin Grenade

As an additional cost to cast this spell, sacrifice a Goblin.
Goblin Grenade deals 5 damage to any target.

Tarfire

Mountain

Goblin Bombardment

Sacrifice a creature: This enchantment deals 1 damage to any target.

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.

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.

Legion Warboss

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
At the beginning of combat on your turn, create a 1/1 red Goblin creature token. That token gains haste until end of turn and attacks this combat if able.

Goblin Ringleader

Haste (This creature can attack and {T} as soon as it comes under your control.)
When this creature 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.

Goblin War Drums

Creatures you control have menace. (They can't be blocked except by two or more creatures.)

Goblin Wardriver

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)

Foundry Street Denizen

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

Goblin Matron

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

Goblin Chainwhirler

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

Warren Instigator

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

Goblin Recruiter

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

Fanatical Firebrand

Haste (This creature can attack and {T} as soon as it comes under your control.)
{T}, Sacrifice this creature: It deals 1 damage to any target.

Krenko, Mob Boss

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