The Crackler is an item, first appearing in Kirby's Return to Dream Land which fires repeated small cannonballs at an arc when carried.
The Crackler is red with gold accents and a blue star on its base. The star changes color as the Crackler becomes more unstable, eventually flashing red to indicate that it will break soon.
The Crackler can be picked up, carried, and thrown like many other items. Similarly, the character holding the Crackler can only make one jump and cannot use any attack but Slide. When thrown, the Crackler itself can deal minor damage to enemies. The main selling point of carrying the Crackler is that, while held, it will repeatedly and rapidly fire cannonballs in an arc in front of it, heavily damaging any enemies caught in its fire and destroying blocks, including Metal Blocks in its wake.
Effective use of the Crackler is required to obtain certain collectibles, including several Energy Spheres.
Kirby's Return to Dream Land
The Crackler first appears in this title, where it can be found at various points in stages. When the item appears, it cannot be reset unless the stage is restarted or Kirby is KOed. The Crackler can be carried into other rooms, but it cannot be carried out of the stage itself.
The Crackler also appears in the Items Challenge Stage.
Kirby: Triple Deluxe & Kirby Fighters Deluxe
The Crackler also makes an appearance in Kirby: Triple Deluxe, specifically in the Kirby Fighters Sub-Game. It serves the same function as before, though it burns out more quickly and its arc is smaller. This item carries over to the expanded version of the game, Kirby Fighters Deluxe.
Kirby Fighters 2
The Crackler returns in Kirby Fighters 2, serving the same purpose as in Kirby Fighters Deluxe. In this game, there are items in Story Mode: The Destined Rivals which can be used to power up the Crackler when Kirby is carrying it.