Master Crown

"The source of limitless power...The Master Crown!"

- Magolor

The Master Crown is a seemingly malevolent item in Kirby's Return to Dream Land. It was first seen when Kirby, Magolor, and co. enter Halcandra via the Lor Starcutter, resting atop Landia's head and remaining dormant until the battle against Landia. After Landia's defeat, the Master Crown falls from its spot onto the ground, only to be seized by Magolor soon after. Magolor then reveals that he fought Landia himself for the crown, but he lost, later fleeing to planet Popstar - this may have been why Landia attacked the Lor Starcutter on sight earlier. The crown transforms Magolor into a ghastly, jester-like creature as he makes his move to conquer the entire universe, starting with Popstar. After defeating Magolor the final time, the Master Crown shatters as Magolor fades away.

Physical Appearances
The Master Crown is known to change it's overall shape throughout the course of the game. It comes in four forms:
 * When atop Landia's head, it resembled a typical crown with spikes extending from its jewel and base.
 * When Magolor first tried it on, it morphed into a larger crown, wherein the base spikes resembled dragon claws and the jewel spikes weren't present. When Magolor transforms into Magolor EX the jewel on the crown turns red instead of its original greenish blue color but is otherwise unchanged.
 * When Magolor transformed again, the crown grew and wrapped around parts of his body; the claws remained intact, but the top of the crown changed, no longer resembling a typical crown, featuring four protruding structures and some of it grew out and formed Magolor's wings.
 * When "worn" by Magolor Soul (seeing how it has now possessed Magolor it is debatable whether or not he can be said to be consciously wearing it), the crown changed into a white crown with two additional spikes extending from the side, two curled spikes extending from the back, and black spikes protruding from many parts of the crown. The jewel also changed color, bearing red, purple, and orange shades.

Trivia

 * The Master Crown is likely a sentient entity. Magolor Soul's VS quote says it is "no more than a manifestation of the crown itself". This idea is supported by the fact that Magolor didn't actually put on the crown, but, rather, it floated to his head after Magolor held it in his hands. While sitting on Magolor's head before the battle against Magolor Soul (and by extension its normal mode counterpart), it can be seen occasionally wiggling and moving about on its own, perhaps trying to possess (or communicate with) Magolor.
 * Interestingly, in all of its forms except for its first, an eye-like pattern is clearly discernable around and including the crown's jewel, perhaps as a subtle indicator of the crown's sentience, an implication of it being omniscent (or all-knowing), or even implying that it is guiding Magolor's course of action. If the latter is correct, this also implies that Landia was not possessed by the crown at any point, suggesting that part of the reason Landia was guarding it was to prevent the crown from attempting universal domination (as it seems to have been trying to do when it possessed Magolor Soul).
 * Assuming it is indeed sentient, the Master Crown is one of the few items with sentience in the series to not help Kirby, arguably posing as a main antagonist instead by possessing Magolor and forcing him to do its bidding.