Zero (ゼロ, Zero), codenamed Zero One (01 (ゼロワン), Zero Wan), is the final boss in The King of Fighters 2000. He is one of the higher-ranked agents of NESTS, a fictional organization that desired to take over the world, and the clone to Zero.
In the developer's comments section on the King of Fighters anniversary site, KOF series's producer, C.A.C Yamasaki, admits basing Zero's design off a certain character from the manga Fist of the North Star. The names of his moves mirror the names of techniques used by the three Rashō, Kaioh, Hyou and Han (creators have also alluded to the homage as intentional).
During The King of Fighters '99, Zero was commanded to watch over the performance of the Kusanagi cloning process, set forth by one of their lower ranked officers, Krizalid. Acting as the project supervisor, he monitored all actions done by Krizalid and also analyzed the performance of K'. After he neutralizes the Kyo clones and terminates Krizalid, he begins to secretly build his own weapon from NESTS' technology called the "Zero Cannon", setting it to operate with the same technology found in Krizalid's battle armor.
He sets his plans into motion in The King of Fighters 2000. There, he impersonates Ling, a military commander and close friend to Heidern. Using his Ling persona as a decoy, he tricks and captures Heidern to stop the military resistance against him. He then fights the winning team of the tournament, planning to use their fighting capacities to power his Zero Cannon. His plans were foiled by Kula Diamond, Foxy, Diana and Candy Diamond. The game's story highly implies that he is killed by Whip after he privately reveals some shocking information to her (this is made more clear in the Japanese version where she aims her gun at him and the shot is audible).
In spite of being Zero's clone, this Zero is very ambitious and betrayed NESTS to fulfill his ideals. He dislikes traitors, which is ironic and hypocritical since he is a traitor himself. As a master impersonator, Zero is able to mask his own personality and copy the personality of others.
- The Dark Arts - Zero has several powers related to darkness.
- Shadow Trap - Zero can stretch his own shadow and make it hold the enemy's feet.
- Dark Explosion - Zero can create a small explosion of dark energy.
- Black Hole - Zero can create a black hole by punching the ground or simply opening his hands.
Zero relies on his special suit to fight. He knows some basic fighting moves, but uses his suit's blades to fight. The bladed portion of his armor has been called a "skirt" or a "cape," but seems to resemble a Javanese male sarong, only with blades sewn into the lining.
Like his progenitor, he had no crouching attack animations, yet had standing attacks that must be guarded low, and could not crouch initially like typical SNK bosses. These animations and ability were gained as he was added in KOF2002UM.
The developers have also made several jokes at the expense of one of Zero's attacks, wherein he stuns the opponent, and turns away, as an unseen burst of energy causes his bladed cloak to blow upward. This has been jokingly dubbed by the developers as the "Zero Fart", and is even lampooned in the 4-panel KOF comic strips. The move itself is a Fist of the North Star reference.
- Slasher Zero - The King of Fighters 2000, The King of Fighters: All Star
- Dark Gravitation - The King of Fighters 2002 Unlimited Match
- Kinta Futogane - The King of Fighters 2000~2002 UM
- Taiten Kusunoki - The King of Fighters: World
- Jiro Saito - The King of Fighters All Star
- Kaya Okuno - The King of Fighters All Star (As Female Version)
- The King of Fighters 2000 - final boss
- The King of Fighters 2002: Unlimited Match - possible final boss
- The King of Fighters '98 Ultimate Match Online
- The King of Fighters World - unplayable
- The King of Fighter All Star
- Zero Clone like his original has an alternate version in The King of Fighters All Star, called Lady Clone Zero. She does the same specials as his male counterpart except with the shadow attacks were she rammed her opponents rather than make a fart pose and her final skill she creates a black hole by punching the floor like Zero in KOF 2000, also she wears a hairpin and a fake moustache as a pun to Clone Zero.
- Ling, the name of the officer Cloned Zero impersonated, also means "zero" in Mandarin Chinese (零 líng).
- Cloned Zero shows that he doesn't have a defined face as his facial expressions gets horribly contorted when he's dizzy. It's probable that his current face is the one that Ling originally had before he got killed himself.