Foundry Street Denizen

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

Goblin Wardriver

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

Goblin Bushwhacker

Kicker {R} (You may pay an additional {R} as you cast this spell.)
When this creature enters, if it was kicked, creatures you control get +1/+0 and gain haste until end of turn.

Reckless One

Haste
Reckless One's power and toughness are each equal to the number of Goblins on the battlefield.

Boggart Shenanigans

Whenever another Goblin you control is put into a graveyard from the battlefield, you may have Boggart Shenanigans deal 1 damage to target player or planeswalker.

Goblin Trailblazer

Menace (This creature can't be blocked except by two or more creatures.)

Boggart Brute

Goblin Gathering

Create a number of 1/1 red Goblin creature tokens equal to two plus the number of cards named Goblin Gathering in your graveyard.

Mogg Flunkies

Mogg Flunkies can't attack or block alone.

Stingscourger

Echo {3}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Stingscourger enters, return target creature an opponent controls to its owner's hand.

Knucklebone Witch

Whenever a Goblin you control is put into a graveyard from the battlefield, you may put a +1/+1 counter on Knucklebone Witch.

Volley Veteran

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