Hobgoblin Bandit Lord

Other Goblins you control get +1/+1.
{R}, {T}: This creature deals damage equal to the number of Goblins that entered the battlefield under your control this turn to any target.

Swamp

Searslicer Goblin

Raid — At the beginning of your end step, if you attacked this turn, create a 1/1 red Goblin creature token.

Goblin Instigator

When this creature enters, create a 1/1 red Goblin creature token.

Claim the Firstborn

Gain control of target creature with mana value 3 or less until end of turn. Untap that creature. It gains haste until end of turn.

Mountain

Skirk Prospector

Howlsquad Heavy

Start your engines!
Other Goblins you control have haste.
At the beginning of combat on your turn, create a 1/1 red Goblin creature token. That token attacks this combat if able.
Max speed — {T}: Add {R} for each Goblin you control.

Goblin Negotiation

Goblin Negotiation deals X damage to target creature. Create a number of 1/1 red Goblin creature tokens equal to the amount of excess damage dealt to that creature this way.

Goblin Bombardment

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

Goblin Digging Team

{T}, Sacrifice this creature: Destroy target Wall.

Goblin Ski Patrol

{1}{R}: This creature gets +2/+0 and gains flying. Its controller sacrifices it at the beginning of the next end step. Activate only once and only if you control a snow Mountain.

Goblin Trashmaster

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

Boggart Mob

Champion a Goblin (When this enters, sacrifice it unless you exile another Goblin you control. When this leaves the battlefield, that card returns to the battlefield.)
Whenever a Goblin you control deals combat damage to a player, you may create a 1/1 black Goblin Rogue creature token.

Shattergang Brothers

{2}{B}, Sacrifice a creature: Each other player sacrifices a creature.
{2}{R}, Sacrifice an artifact: Each other player sacrifices an artifact.
{2}{G}, Sacrifice an enchantment: Each other player sacrifices an enchantment.

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Volley Veteran

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

Siege-Gang Commander

When this creature enters, create three 1/1 red Goblin creature tokens.
{1}{R}, Sacrifice a Goblin: This creature deals 2 damage to any target.

Mad Auntie

Other Goblin creatures you control get +1/+1.
{T}: Regenerate another target Goblin.

Sling-Gang Lieutenant

When this creature enters, create two 1/1 red Goblin creature tokens.
Sacrifice a Goblin: Target player loses 1 life and you gain 1 life.

Oxidda Daredevil

Sacrifice an artifact: This creature gains haste until end of turn.

Grumgully, the Generous

Each other non-Human creature you control enters with an additional +1/+1 counter on it.

Custody Battle

Enchant creature
Enchanted creature has "At the beginning of your upkeep, target opponent gains control of this creature unless you sacrifice a land."

Munitions Expert

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

Vexing Shusher

This spell can't be countered.
{R/G}: Target spell can't be countered.

Rundvelt Hordemaster

Other Goblins you control get +1/+1.
Whenever this creature or another Goblin you control dies, exile the top card of your library. If it's a Goblin creature card, you may cast that card until the end of your next turn.

Boartusk Liege

Trample
Other red creatures you control get +1/+1.
Other green creatures you control get +1/+1.

Frogtosser Banneret

Haste
Goblin spells and Rogue spells you cast cost {1} less to cast.

Siege-Gang Lieutenant

Lieutenant — At the beginning of combat on your turn, if you control your commander, create two 1/1 red Goblin creature tokens. Those tokens gain haste until end of turn.
{2}, Sacrifice a Goblin: This creature deals 1 damage to any target.

Goblin Bird-Grabber

{R}: This creature gains flying until end of turn. Activate only if you control a creature with flying.

Brightstone Ritual

Add {R} for each Goblin on the battlefield.

Onslaught

Whenever you cast a creature spell, tap target creature.

Disharmony

Cast this spell only during combat before blockers are declared.
Untap target attacking creature and remove it from combat. Gain control of that creature until end of turn.

Goblin Sharpshooter

This creature doesn't untap during your untap step.
Whenever a creature dies, untap this creature.
{T}: This creature deals 1 damage to any target.

Goblin Piledriver

Protection from blue (This creature can't be blocked, targeted, dealt damage, or enchanted by anything blue.)
Whenever this creature attacks, it gets +2/+0 until end of turn for each other attacking Goblin.

Goblin Balloon Brigade

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

Forest

Treasure Nabber

Whenever an opponent taps an artifact for mana, gain control of that artifact until the end of your next turn.