Frogify

Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Goblin Piledriver

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

Izzet Boilerworks

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Fervor

Creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Krenko, Mob Boss

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

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Dragonshift

Until end of turn, target creature you control becomes a blue and red Dragon with base power and toughness 4/4, loses all abilities, and gains flying.
Overload {3}{U}{U}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Island

Mountain

Sol Ring

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Teleportal

Target creature you control gets +1/+0 until end of turn and can't be blocked this turn.
Overload {3}{U}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Siege-Gang Commander

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

Skirk Prospector

Negate

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mizzium Mortars

Mizzium Mortars deals 4 damage to target creature you don't control.
Overload {3}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Krenko, Tin Street Kingpin

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