Goblins of the Flarg

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)
When you control a Dwarf, sacrifice this creature.

Goblin Balloon Brigade

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

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Mountain

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Ankh of Mishra

Whenever a land enters, this artifact deals 2 damage to that land's controller.

Goblin King

Other Goblins get +1/+1 and have mountainwalk.

Goblin Chirurgeon

Sacrifice a Goblin: Regenerate target creature.

Shivan Dragon

Flying
{R}: This creature gets +1/+0 until end of turn.

Winds of Change

Each player shuffles the cards from their hand into their library, then draws that many cards.

Black Vise

As this artifact enters, choose an opponent.
At the beginning of the chosen player's upkeep, this artifact deals X damage to that player, where X is the number of cards in their hand minus 4.

Wheel of Fortune

Each player discards their hand, then draws seven cards.

Manabarbs

Whenever a player taps a land for mana, this enchantment deals 1 damage to that player.

Fork

Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.