Goblins replaced Creepers in the June 6th, 2015 update. They are a special monster, the ability to become a goblin shows up randomly in the monster menu.
Goblins' main priority is to destroy walls and scatter dwarves. They spawn with 12 Boom Boxes, Goblin Pick, and "Kaboom!"
Goblins have 26 heath(13 hearts) instead of upgrading to get max 40 heath(20 hearts) otherwise they are fully maxed out and even have a wider "Kaboom!" range by 1 block.
Goblin Pick Edit
This is a weak wooden pick that allows goblins to dig through a few blocks of stone. Goblin Pick deals 4 damage (2 hearts) and 25 armor damage.
Goblin Boom Box Edit
This is the main way Goblins can scatter dwarves and destroy walls.
Left Clicking a Boom Box uses 2 boxes and throws a piece of lit TNT with 3 second detonation time, which deals 6 (3 hearts) damage and 50 armor damage knocking back dwarves with a 5 block radius, and damages walls down to cobble.
Right-Clicking places a Boom Box. After 10 seconds, the Boom Box will explode and deal damage to the wall. If at any point before the detonation a dwarf hits the Boom Box, the Boom box will be destroyed, including shooting it with an arrow, good for keeping distance but foiling Goblins. The Goblins have place limits, one per three seconds, with a stash of Boom Boxes that regenerates one Boom Box per second. Boom Boxes deal 10 armor damage to dwarves.
This item is a piece of gunpowder that causes the Goblin to self-destruct with the power of 2 boxes dealing 50 damage (5 hearts) and 50 armor damage, "Kaboom!"(s) have a destruct timer, of around five seconds. However, if a dwarf manages to intercept the Kaboom or the goblin takes damage, the Kaboom will be reset unless it is reactivated by left-clicking it again, or a dwarf kills the gobo.