|“||Necrodeus hates light and wants to steep the world in darkness. As a pirate, I can respect that. But with no light, all my treasure would cease sparkling. And I can't have that. Do everything in your power to stop him. My gold must shine!”|
|— Daroach • Kirby Mass Attack|
Necrodeus is the main villain of Kirby Mass Attack. He also serves as the final boss in the game.
He has red eyes and a head that resembles a horned skull with matching bony hands. He has a third eye socket in the middle of his forehead, but no eye is seen within. Necrodeus has two curved horns on the sides of his head and a third horn, but straighter and shorter than the other two on top of his head. Inside his mouth are several sharp fangs and he also has a purple clown-like nose. His body is made of purplish black smoke, which during the beginning cutscene almost resembles Nightmare's cloak. Around his neck is a necklace made completely out of skulls. He wields a black staff with a purple jewel in its top which he uses to decimate Kirby at the beginning of the game, but swallows it in the cutscene before the final battle, requiring Kirby to destroy him in order to retrieve it. When Necrodeus attacks, he reveals that he has an extra Zero-like (specifically, Zero after his core broke away) appendage inside his mouth, which he uses to fire a laser beam.
Necrodeus has multiple attacks, all which can KO a Kirby in one hit. First, he will use his remote hands to smash the ground below him and try to close his palms around the Kirbys. He will also use his index fingers to produce sparks of electricity.
He uses other attacks as well in his third phase. These moves include spitting out metal objects that shoot lasers in different directions, producing larger sparks that bounce off of the screen, and using an eyeball on the inside of his mouth to produce a blast of energy. Necrodeus also has help from Skullions, horned versions of Skullys. Skullions, like normal Skullys, turn purple and have the ability to snatch a Kirby from the player's grasp. If a Kirby is grabbed, the Skullion will float over to Necrodeus, who will devour the Kirby and eliminate it from the fight.
If the eyeball inside his mouth takes enough damage, his head will crack and shake rapidly. If the head is attacked, the player will be required to tap as fast as they can. If the player fills the bar, Necrodeus' skull will be destroyed, ending the game and allowing the 10 Kirbys and their heart to become one whole being again.
- In the beginning of the game, Necrodeus has a cape, but it is not seen in the final battle. Instead, he wears a necklace of skulls.
- Necrodeus seems to emit a deep metallic cackle in battle, making him the one of four final bosses to cackle during the fight against him, the other three being Drawcia, Marx, and Marx Soul.
- Necrodeus, Dark Mind, Wham Bam Jewel, and Magolor Soul are the only bosses in the series to have exactly three eyes.
- Necrodeus's appearance changes from the cutscenes to the boss battle; he gains hands with a less "boney" appearance, his horns are a bit more curved, and he now dons a more pinkish nose.