Goblin King

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Mogg Conscripts can't attack unless you've cast a creature spell this turn.

Provoke (Whenever this creature attacks, you may have target creature defending player controls untap and block it if able.)

As an additional cost to cast this spell, sacrifice a Goblin.
Goblin Grenade deals 5 damage to any target.

Haste (This creature can attack and {T} as soon as it comes under your control.)

Whenever Mogg Maniac is dealt damage, it deals that much damage to target opponent or planeswalker.

Sacrifice Mogg Fanatic: It deals 1 damage to any target.

When Goblin Recruiter enters, search your library for any number of Goblin cards, reveal them, then shuffle and put those cards on top in any order.

Incinerate deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.