Demolitionist

The Demolitionist is an NPC vendor that will spawn once the following criteria have been met:
 * There is an empty house.
 * You have one of the Explosive Consumables in your inventory.

Once the Demolitionist has moved into a house, he will sell the following:

The Demolitionist's appearance seems to be based on dwarves from many games, films and works of literature. He is significantly shorter than other NPCs and has a beard. Furthermore, his mining helmet, lantern, and the fact that he sells explosives fits the trope of dwarves preferring underground environments. He and the Arms Dealer also seem to have a rivalry.

Quotes
"Dynamite, my own special cure-all for what ails ya."

"Explosives are da' bomb these days. Buy some now!"

"Why purify the world when you can just blow it up?" (Only if Dryad is present.)

"It's a good day to die!"

"I'm sure the nurse will help you if you accidentally lose a limb to these." (Only if Nurse is present.)

"I wonder what happens if I... (BOOM!)... Oh, sorry, did you need that leg?"

"Even the gun dealer wants what I'm selling!" (Only is Arms Dealer is present.)