Star Merchant

The Star Merchant (lit. 星际商人) is an NPC vendor who sells various exclusive items for both in-game coin and real-world currency.

They will spawn once the following conditions have been met:
 * There is an empty House.
 * All players in the game world total more than between them in their inventories.

Note that only coins in the main inventory or coin slots are counted; savings stored in a portable storage item like the Piggy Bank do not count toward the requirement. If the Star Merchant is killed, they will only respawn if the above conditions are met again. This means all players need to have over in their combined inventories.

Items sold
Unlike most other merchants, the Star Merchant's stock was not fixed and was instead determined by the game's remote servers. The following items are known to have been sold by the Star Merchant:

Interaction quotes

 * "You have absolutely no idea how much mud blocks sell for abroad." ("你完全不知道泥块在国外卖多少钱. ")
 * "The most valuable thing in my life is to trade coal for a diamond sword!" ("我这辈子最值的事情就是用煤炭换了一把钻石剑！")

Night:
 * "I bet these guys burn up in no time!" ("我打赌这些家伙一会儿就烧起来了！")

Blood Moon:
 * "What's the panic, at least the skeletons here don't ride spiders, do they?" ("慌什么，至少这里的骷髅不会骑蜘蛛，不是吗？")

Trivia

 * The Star Merchant's gender is unknown.
 * The line "You have no idea how much mud blocks sell for overseas." mimics a similar line of the Merchant's, who says the same thing about Dirt Blocks.
 * Most of the Star Merchant's quotes are references to the video game Minecraft:
 * Their dialogue about trading coal for a diamond sword is likely a reference to how Minecraft's Villagers, whose trades include buying coal and selling diamond gear.
 * Their dialogue about enemies burning is a reference to how several hostile creatures in Minecraft burn in sunlight.
 * Their dialogue about skeletons riding spiders is a direct reference to the Spider Jockey mob in Minecraft.