Truffle

The Truffle is an NPC that sells various items such as the Autohammer, Hammush and Mushroom Spear. To get the Truffle to move in, there must be housing in a surface Mushroom Biome during Hardmode. It's very recommendable to prepare a suitable house for him before defeating the Wall of Flesh, as the Mushroom Spear he sells is the strongest spear in the game and is an overall very powerful weapon and can attack through walls, and it's available to acquire in very early hardmode as soon as the NPC arrives.

Items sold
Once the Truffle has moved into a house, he sells the following:

Names
Truffle may have any of the following names: Maitake, Muscaria, Shimeji, Amanita, Porcini, Reishi, Shiitake, Chanterelle, Agaric, Morel, Enoki and Cremini.

Quotes

 * "There's been such a huge rumor that's being spread about me, 'if you can't beat him, eat him!'"
 * "Everyone in this town feels a bit off. I woke up to the clothier chewing on my foot last night."
 * "As if living underground wasn't bad enough, jerks like you come in while I'm sleeping and steal my children."
 * "You haven't seen any pigs around here have you? My brother lost his leg to one."
 * "I tried to lick myself the other day to see what the big deal was, everything started glowing blue."
 * "Between you and me, [Dryad's name] is the only one I trust. She is the only one here who hasn't tried to eat me or use me in a potion."
 * "Everytime I see the color blue, it makes me depressed and lazy."
 * "I don't know the 'Truffle Shuffle', so stop asking!"

Trivia

 * All of his names are named after a type of mushroom or toadstool.
 * The "Truffle Shuffle" line is a reference to the movie "The Goonies"
 * Truffle's line about "everything glowing blue" may imply that the blue mushrooms are hallucinogenic.
 * The line "Everytime I see the color blue, it makes me depressed and lazy", may be referring to the fact that he is an underground creature, as opposed to most diurnal animals, who become more active when exposed to the sky. Or it could be a joke because the entire Mushroom Biome (as well as himself) is blue. It could also simply be a joke referring to the slang term "blue" which indicates a person is sad or depressed, thus, seeing the color blue makes him feel "blue".
 * The line "you haven't seen any pigs around here have you? My brother lost his leg to one." refers to the fact that most pigs love Black Truffle mushrooms.
 * The line 'if you cant beat him, eat him' may be a reference to the Children's television show Kirby, right back at ya where that line is used in the shows main theme song.
 * His line "Between you and me, [Dryad's name] is the only one I trust. She is the only one here who hasn't tried to eat me or use me in a potion." this is a reference to how Glowing Mushrooms can be used to create Healing Potions or could be eaten before 1.2 to restore Health.