Arms Dealer

The Arms Dealer is an NPC vendor that will spawn once the following criteria have been met:
 * There is an empty house.
 * You have acquired a gun (the gun must be in your inventory, not just stored in a chest somewhere).

The easiest gun to acquire for this purpose is the Musket, which can be obtained by destroying a Shadow Orb.

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

Quotes
"Keep your hands off my gun, buddy!"

"Don't bother with that firework vendor, I've got all you need right here."

"I see you're eyeballin' the Minishark.. You really don't want to know how it was made."

"Make it quick! I've got a date with the nurse in an hour."

"That dryad is a looker. Too bad she's such a prude."