Pixie

The Pixie is a Hardmode enemy which hovers a limited height over ground, commonly spawning in The Hallow at the surface layer. It emits a fair amount of flickering light, and can inflict the Slow or Silenced debuffs. It always drops Pixie Dust, a common Hardmode crafting material.

Pixies are immune to the Poisoned, On Fire!, and Cursed Inferno debuffs.

Trivia

 * The Fairy Bell summons a Fairy which looks similar to a Pixie, and serves as a light source to players.
 * It is possible for a Pixie to drop both the Megaphone and the Fast Clock upon death and both with the same prefix (tested).
 * The Pixie's design may be a nod to a fairy design from The Legend of Zelda, in which some fairies are spheres of colored light with wings.
 * The Megaphone could also be a reference to a Legend of Zelda fairy named Navi. Navi will periodically shout "Hey, Listen!" whenever she has something to say to the player.