Green Cap

The Green Cap is a vanity item equipped in the social helmet slot. It is dropped by the Guide but only when his name is 'Andrew' (names are chosen at random from a list when the Guide spawns).

Trivia

 * The Green Cap drops only from a Guide with the name 'Andrew'. It is a reference to the lead programmer of Terraria, Andrew Spinks.
 * Wearing the Green Cap with Red's Breastplate and Red's Leggings still trigger the visual effect as if you were wearing Red's Helmet.
 * The Green Cap itself seems to be a reference to Luigi, from the Mario games.