Zero Two also known as 02 (Zero-two or Zero-squared) is the main villain and final boss of the Kirby game Kirby 64: The Crystal Shards. It is revealed that Zero Two (O₂ was the leader of the Dark Matter that attacked Ripple Star and destroyed the crystal Ribbon was holding during the opening scene of the game, before she met Kirby. While it is believed to be resurrected from Zero's remains, this is debatable.
O₂'s appearance is an imperfect, white sphere. He possesses a single red eye, two wings covered in blood, a bandage on his head, a yellow halo, which changes color when hit, and has a spike at the bottom, where later a thorny vine pops out.
The requirements for battling O₂ is to collect all 100 Crystal Shards. Once the player collect the last shard, the player had to beat Miracle Matter, regardless if it was defeated before. After meeting this requirements, Dark Star is unlocked, where a small level, where Zero Two resided.
The battle takes place in the air, where Ribbon carries Kirby, who has the Crystal Ability, along with the Ribbon Ability. During his introduction, Zero Two appears, bearing a kind face that resembles that of an angel, but this is a facade: the mouth becomes an eye and the black eyes fade. In order to damage O₂, the player had to fire crystals in O₂'s eye, while dodging the explosives O₂ send at Kirby. After damaging O₂'s eye enough, the player had to shoot the halo, without O₂ attacking. Once the halo was destroyed, the player had to shoot the vine coming out from below O₂, while dodging green smoke. This is the only spot where O₂'s health bar drops down. After that, the entire process start again. The player also can shoot and destroy O₂'s wings, making it slower. After the fight, O₂ gives of a bright light, and Dark Star explodes as the gang escapes. O₂ is never seen again thereafter.
- Zero Two is one of the few Kirby characters that actually bleed when fought, the others being Zero, Dark Meta Knight, Shadow Dedede and Star Dream.
- He is also one of the creepiest Nintendo bosses due to this.
- Void Soul has an idle pose where he makes the same face Zero Two had in his intro. As Void - Astral Birth, Void Soul does this in his pause screen description, albeit facing slightly downward.