Dark Nebula (also known as Dark Zero in the Japanese version) is the overarching antagonist and final boss of Kirby: Squeak Squad.
He is an evil demon star who was inside a treasure chest owned by King Dedede.
Dark Nebula was the Ruler of the Underworld ("Lord of Darkness" in the original Japanese version). He was sealed in a chest long ago, not known why.
This chest was later confused with other things - Kirby thought the chest contained his strawberry shortcake, and the Squeaks thought it contained ultimate power. By the time Kirby made his way through Ice Island and beat Daroach, Kirby was about to take the chest Daroach had - but then Meta Knight took it, knowing what was actually in there. Kirby and the Squeaks then set out to reclaim the chest - still not knowing what was actually inside. After Kirby gets through the Secret Sea and beats Meta Knight, he walks towards the chest - but this time, Daroach gets his hands on the chest and opens it. But when Daroach opens the chest, Dark Nebula comes out (in the form of mist whose particles resemble stars of his colours) and possesses the Squeaks's leader. Daroach's fur and clothing turn purple, and the Squeaks take off to Gamble Galaxy.
After venturing through Gamble Galaxy, Kirby finally fights and defeats the possessed Daroach. Dark Nebula (taking on a recoil star's form, albeit his own colour) then leaves Daroach's body and flees, turning him back to his normal self. Kirby then takes Daroach's scepter and follows Dark Nebula to a crystalline battlefield. Dark Nebula uses his power to reassemble his body, eye included. There, Kirby battles Dark Nebula and defeats him, destroying him forever.
Dark Nebula's main form of attacking is launching stars at Kirby from an angle (usually the side of the arena). Dark Nebula also has three alternative forms. While changing forms, the screen will flash white. If Kirby bumps into him, he will be damaged depending on what form Dark Nebula has (i.e. burned, electrocuted, frozen).
In his fire form, Dark Nebula can shoot stars that can burn Kirby. His strongest attack in this form is releasing a large fire ball that slowly approaches the ground and explodes, thus creating a vertical fire blast. The easiest way to dodge this is to float by the side of the screen. The fireball can be destroyed to cancel out the attack. On the sides of the blast are rows of lingering flames. Also in this form he will move at great speeds in angles. This physical attack is hardest to dodge, but only when Kirby is floating in his range of where he flies.
In his electric form, Dark Nebula will shoot stars at Kirby that can shock him. His physical attack involves moving in a zigzag pattern. His strongest attack is releasing four electric streams diagonally in all directions then discharging them to create an electric frame that covers all sides of the arena. This attack is the hardest to dodge. The best way to dodge this is to first stand on the middle of the battlefield, wait for Dark Nebula's diagonal electric shocks to disappear, then, at the right moment, jump before Kirby gets hit by the electrical frame.
In his ice form, Dark Nebula shoots out stars that can freeze Kirby. His physical attack involves going around the arena in a circle. Occasionally while doing this, he will float back and forth across the stage in an arc. His special attack is firing an ice laser at the ground as he goes along, thus freezing it. This hinders Kirby's traction so that Dark Nebula can't be dodged as easily while attacking
Dark Nebula resembles a giant, black star. He has purple flames erupting from his sides. In his centre is a single pink eye with a black pupil about the size of Kirby's eyes. Dark Nebula's default form is only seen temporarily at the start of his battle and his elemental forms are fought instead.
After he ejects himself from Daroach's body, Dark Nebula resembles a blackened recoil star with a purple outline.
- Dark Nebula is similar to the Dark Star from the Mario & Luigi series, as he has a star shape and desires to destroy the world.
- He is also similar to Infinite from Sonic Forces.
- His title of "Lord of Darkness" is one of many minor references to the anime, where Nightmare is called the Emperor of Darkness.
- The symbol for the Triple Star shows three stars, one blue, one green, one red, and these are also the colors of Dark Nebula's forms. This shows that, like the Triple Star, he uses the power of the three elements – Fire, Ice, and electricity (Spark) – which are emphasized more in this game than in any other.
- His name is Dark Zero in Japan. This led some fans to believe that Zero returned in a "demon possessed" form, and their physical appearances are remotely similar. However, the characters have different back stories, and all spawn of Dark Matter are usually in Zero's direct control anyway (there are exceptions, such as Gooey).
- Dark Nebula's behavior has a passing resemblance to that of Miracle Matter.
- It is quite possible that Dark Nebula is simply a rogue form of Dark Matter that does not take orders from Zero, this is evidenced by his similar fighting style shared with Miracle Matter, his ability to possess others like normal Dark Matter and his eye having a striking resemblance with Zero himself.
- It is not known what Dark Nebula had intended to do once he had possessed Daroach and the Squeaks. Although if one views the Stage Select screen of the Gamble Galaxy, they can see that the final battle between Kirby and Dark Nebula takes place deep within a black hole that has seemingly appeared from nowhere. Due to the close proximity of the giant gravity well and Pop Star, Dark Nebula may have been trying to destroy the planet.
- It is possible that Dark Nebula is actually some form of Dark Matter with gained sentience. This could explain why his battle strategy is identical to Miracle Matter's in terms of behavior, as well as the similar coloration of Dark Daroach and Dark Matter's first form. It is also theorized to be the original blob of Dark Matter which attacked Dream Land way back in Kirby's Dream Land 2, which may explain why King Dedede had sealed it in a chest.
- Kirby can easily dodge Dark Nebula's attacks by floating directly at the top corners.
- Dark Nebula uses fire, ice, and electrical powers which are similar to Flamberge, Francisca, and Zan Partizanne.
- One of Daroach's attacks in Kirby Star Allies involves him placing down a chest, and a fake Dark Nebula springs out.
- His star shape strangely looks similar to warp stars.