Zero

Zero (referred to as ? in Kirby's Dream Land 3 ' s bad ending) is the final boss of Kirby's Dream Land 3 who resembles Dark Mind's second and third form. Zero is first seen in the Dark Matter oblivion Hyper Zone.

Background
Zero's association with Dark Matter, as well as its role as the final boss and its capability to produce Dark Matter from its body in the fight suggests that it is a source, if not the source of Dark Matter, and at the very least, an intelligence which drives motivation behind events involving Dark Matter. Kirby manages to defeat it after the events of Kirby's Dream Land 3, but Zero soon returns as 0² in Kirby 64: The Crystal Shards.

Zero is unique as a villain or final boss, since no backstory is known about it, and the only thing it is ever seen to be personally doing is fighting Kirby at the end of the game. Hence the only hints towards its motivations are from the events around Dark Matter, which tends to revolve around infesting certain planets. While likely to be attempts at controlling the planets, they never came to fruition; so it is not known what Zero, if it is indeed the intelligence Dark Matter follows, intends to do with Dark Matter-infested planets. The somewhat unusual name of the Love-Love Stick, which is the weapon Kirby uses against its first incarnation at the end of Kirby's Dream Land 3, suggests that it is weak to certain happy emotions.

Kirby's Dream Land 3
Zero and Dark Matter are the extra, final bosses in the game. They can only be fought if Kirby has collected all of the Heart Stars. If not, the game simply ends after Kirby defeats the possessed Dedede and an ominous, dreary ending plays. Together, the two evil entities are fought inside the Hyper Zone.

Right after Kirby delivers the final strike to Dark Matter, the screen begins to flash and Zero suddenly appears. The way it attacks is very similar to Dark Matter; it flies around shooting projectiles at Kirby and attempts to crash into him. In his first form, Zero appears as a giant, round, white sphere, with a small, red eye with a black pupil. It attacks by shooting red goo from openings that appear around its eye and launches miniature Dark Matters at Kirby. Sometimes it moves across the screen in an erratic manner trying to ram into Kirby. Due to its size, this can be difficult to avoid. Sometimes, Zero flies forward, offscreen, and into the background. When it does, it will begin to deploy more blood from its eye, which deals a lot of damage if it makes contact with Kirby. When Zero's Life Meter is depleted, the central part of the eye detaches and begins the final phase of the fight. The eye will then start to circle around Kirby continuously closing in and ramming into him. Ramming Kirby is the eye's only form of attack. It does not have much health, and can be taken down in a short number of hits.

Once its life meter is depleted, Zero spirals out of control, severely hemmoraging, and explodes.

Trivia

 * Dark Mind's final form bears a very strong resemblance to Zero, so a credible inference would be that Dark Mind's final form is possibly the Mirror World equivalent of Zero.
 * Kirby's Dream Land 2 and Kirby Mass Attack are the only games with Dark Matter that Zero does not appear in.
 * According to the size of Dark Matter in Kirby Mass Attack, it appears that it has grown to the size of Zero.
 * Because Zero and its undead counterpart are the only characters who appear to bleed on-screen, they are the most gruesomely depicted bosses in the series.
 * Zero's bloody battle did not affect the E rating of Kirby's Dream Land 3, but later turned the rating of Kirby's Dream Collection from an E to an E10+.
 * This is due, in part, to the fact that the E10+ Rating didn't exist at the time.

Sprites
ゼロ