Voracious Dragon

Flying
Devour 1 (As this enters, you may sacrifice any number of creatures. This creature enters with that many +1/+1 counters on it.)
When Voracious Dragon enters, it deals damage to any target equal to twice the number of Goblins it devoured.

Mountain

Raid Bombardment

Whenever a creature you control with power 2 or less attacks, Raid Bombardment deals 1 damage to the player or planeswalker that creature is attacking.

Rustrazor Butcher

First strike
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Hissing Iguanar

Whenever another creature dies, you may have Hissing Iguanar deal 1 damage to target player or planeswalker.

Goblin Fireslinger

{T}: Goblin Fireslinger deals 1 damage to target player or planeswalker.

Goblin Glider

Outrage Shaman

Chroma — When Outrage Shaman enters, it deals damage to target creature equal to the number of red mana symbols in the mana costs of permanents you control.

Torch Slinger

Kicker {1}{R} (You may pay an additional {1}{R} as you cast this spell.)
When Torch Slinger enters, if it was kicked, it deals 2 damage to target creature.

Goblin Tunneler

{T}: Target creature with power 2 or less can't be blocked this turn.

Goblin Cohort

Goblin Cohort can't attack unless you've cast a creature spell this turn.

Boggart Forager

{R}, Sacrifice Boggart Forager: Target player shuffles their library.

Intimidator Initiate

Whenever a player casts a red spell, you may pay {1}. If you do, target creature can't block this turn.

Goblin Arsonist

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

Goblin Raider

Rally the Forces

Attacking creatures get +1/+0 and gain first strike until end of turn.

Akki Rockspeaker

Goblin Bushwhacker

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

Raging Goblin

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

Smoldering Spires

Smoldering Spires enters tapped.
When Smoldering Spires enters, target creature can't block this turn.
{T}: Add {R}.

Goblin Brigand

Goblin Brigand attacks each combat if able.

Horde of Boggarts

Menace (This creature can't be blocked except by two or more creatures.)
Horde of Boggarts's power and toughness are each equal to the number of red permanents you control.

Mudbrawler Cohort

Haste
Mudbrawler Cohort gets +1/+1 as long as you control another red creature.

Mogg War Marshal

Echo {1}{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 Mogg War Marshal enters or dies, create a 1/1 red Goblin creature token.

Emberwilde Augur

Sacrifice Emberwilde Augur: It deals 3 damage to target player or planeswalker. Activate only during your upkeep.

Fire Juggler

Whenever Fire Juggler becomes blocked, clash with an opponent. If you win, Fire Juggler deals 4 damage to each creature blocking it. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Teetering Peaks

Teetering Peaks enters tapped.
When Teetering Peaks enters, target creature gets +2/+0 until end of turn.
{T}: Add {R}.

Quest for the Goblin Lord

Whenever a Goblin you control enters, you may put a quest counter on Quest for the Goblin Lord.
As long as Quest for the Goblin Lord has five or more quest counters on it, creatures you control get +2/+0.