Brightstone Ritual

Add {R} for each Goblin on the battlefield.

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Zada, Hedron Grinder

Whenever you cast an instant or sorcery spell that targets only Zada, Hedron Grinder, copy that spell for each other creature you control that the spell could target. Each copy targets a different one of those creatures.

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Krenko's Command

Phyrexian Walker

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Ancestral Anger

Target creature gains trample and gets +X/+0 until end of turn, where X is 1 plus the number of cards named Ancestral Anger in your graveyard. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Obstinate Familiar

If you would draw a card, you may skip that draw instead.

Sudden Breakthrough

Target creature gets +2/+0 and gains first strike until end of turn.
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Mountain

Expedite

Target creature gains haste until end of turn.
Draw a card.

Skirk Prospector

Ornithopter

Memnite

Crimson Wisps

Target creature becomes red and gains haste until end of turn. (It can attack and {T} this turn.)
Draw a card.

Titan's Strength

Target creature gets +3/+1 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Ancestors' Aid

Kuldotha Rebirth

As an additional cost to cast this spell, sacrifice an artifact.
Create three 1/1 red Goblin creature tokens.

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Gleeful Demolition

Destroy target artifact. If you controlled that artifact, create three 1/1 red Phyrexian Goblin creature tokens.