Ogre Battledriver

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and {T} this turn.)

Scorching Shot

Scorching Shot deals 5 damage to target creature.

Chandra's Spitfire

Flying
Whenever an opponent is dealt noncombat damage, this creature gets +3/+0 until end of turn.

Bulk Up

Double target creature's power until end of turn.
Flashback {4}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Goblin Gathering

Create a number of 1/1 red Goblin creature tokens equal to two plus the number of cards named Goblin Gathering in your graveyard.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Uthgardt Fury

When Uthgardt Fury enters the battlefield, it deals 4 damage to any target.
Damage isn't removed from creatures your opponents control during cleanup steps.

Scorching Dragonfire

Scorching Dragonfire deals 3 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

Monstrous Rage

Target creature gets +2/+0 until end of turn. Create a Monster Role token attached to it. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample.)

Ruby Medallion

Red spells you cast cost {1} less to cast.

Goblin Gang Leader

When this creature enters, create two 1/1 red Goblin creature tokens.

Urabrask's Forge

At the beginning of combat on your turn, put an oil counter on this artifact, then create an X/1 red Phyrexian Horror creature token with trample and haste, where X is the number of oil counters on this artifact. Sacrifice that token at the beginning of the next end step.

Mountain

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.