Goblin Assailant

Caterwauling Boggart

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

Mountain

Goblin Cadets

Whenever Goblin Cadets blocks or becomes blocked, target opponent gains control of it. (This removes Goblin Cadets from combat.)

Battle Squadron

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

Foundry Street Denizen

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

Battle-Scarred Goblin

Whenever Battle-Scarred Goblin becomes blocked, it deals 1 damage to each creature blocking it.

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.

Boggart Brute

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

Goblin Commando

When Goblin Commando enters, it deals 2 damage to target creature.

Akki Rockspeaker

Goblin Champion

Haste
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Battle-Rattle Shaman

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

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 Arsonist

When Goblin Arsonist dies, you may have it deal 1 damage to any target.

Akki Blizzard-Herder

When Akki Blizzard-Herder dies, each player sacrifices a land of their choice.

Inferno Elemental

Whenever Inferno Elemental blocks or becomes blocked by a creature, Inferno Elemental deals 3 damage to that creature.

Muxus, Goblin Grandee

When Muxus, Goblin Grandee enters, reveal the top six cards of your library. Put all Goblin creature cards with mana value 5 or less from among them onto the battlefield and the rest on the bottom of your library in a random order.
Whenever Muxus attacks, it gets +1/+1 until end of turn for each other Goblin you control.