Developer items

Developer items are vanity items, wings, dyes, and other items, that were made for particular members of Terraria's development staff.

A random set of developer items can rarely (1/20 or 5% chance) drop from a Hardmode boss' Treasure Bag in an Expert mode world.

Trivia

 * Developer items, along with 0x33's Aviators, are the only Expert-exclusive items that do not have the rarity.
 * Some items (unlisted) were used by the developers during game testing, and were removed from normal gameplay, making them unobtainable: Red Potion and Zapinator (the Zapinator was later released on and  1.4.0.1, and the Red Potion is available on   1.4.0.1 in worlds with the seed 05162020).
 * The developer items were unobtainable before the 1.3.0.1 update, and, if somehow worn, most of the items would inflict a variety of debuffs on the wearer, even if worn in the vanity slot, thus rendering them useless. One of the exceptions to this rule were Red's Wings, which would give infinite flight when worn.

History
开发者物品