Foundry Street Denizen

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

Legion Loyalist

Haste
Battalion — Whenever this creature and at least two other creatures attack, creatures you control gain first strike and trample until end of turn and can't be blocked by creature tokens this turn.

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.

Skirk Prospector

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 Warchief

Goblin spells you cast cost {1} less to cast.
Goblins you control have haste.

Squee, Dubious Monarch

Haste
Whenever Squee attacks, create a 1/1 red Goblin creature token that's tapped and attacking.
You may cast this card from your graveyard by paying {3}{R} and exiling four other cards from your graveyard rather than paying its mana cost.

Goblin Javelineer

Haste
Whenever this creature becomes blocked, it deals 1 damage to target creature blocking it.

Conspicuous Snoop

Play with the top card of your library revealed.
You may cast Goblin spells from the top of your library.
As long as the top card of your library is a Goblin card, this creature has all activated abilities of that card.

Krenko, Tin Street Kingpin

Whenever Krenko attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

Mountain

Battle Cry Goblin

{1}{R}: Goblins you control get +1/+0 and gain haste until end of turn.
Pack tactics — Whenever this creature attacks, if you attacked with creatures with total power 6 or greater this combat, create a 1/1 red Goblin creature token that's tapped and attacking.

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.